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Ideas of Ludwig Wittgenstein, by Text

[Austrian, 1889 - 1951, Born Vienna. Aeronautics at Manchester, then philosophy with Russell in Cambridge. Austrian army in WWI. Teacher in the Alps, then back to Cambridge. Died in Cambridge.]

1913	Notes on Logic

B7	p.322	22312	Facts can be both positive and negative
			Full Idea: In 1913 Wittgenstein was explicit that there are both positive and negative facts.
			From: report of Ludwig Wittgenstein (Notes on Logic [1913], B7) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 47 'Mole'
			A reaction: This is a prelude to the Tractatus, in which negative facts are denied in T1.11 (and in a 1919 letter), but then affirmed in T2.06.

1915	Notebooks 1914-1916

§37	p.28	6563	'And' and 'not' are non-referring terms, which do not represent anything
			Full Idea: Wittgenstein's 'fundamental idea' is that the 'and' and 'not' which guarantee the truth of "not p and not-p" are meaningful, but do not get their meaning by representing or standing for or referring to some kind of entity; they are non-referring terms.
			From: report of Ludwig Wittgenstein (Notebooks 1914-1916 [1915], §37) by Robert Fogelin - Walking the Tightrope of Reason Ch.1
			A reaction: Wittgenstein then defines the terms using truth tables, to show what they do, rather than what they stand for. This seems to me to be a candidate for the single most important idea in the history of the philosophy of logic.

14.09.29	p.7	23481	Propositions assemble a world experimentally, like the model of a road accident
			Full Idea: In the proposition a world is as it were put together experimentally. (As when in the law court in Paris a motor-car accident is represented by means of dolls, etc).
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 14.09.29)
			A reaction: [see Tractatus 4.031] This is the first appearance of LW's picture (or model) theory of meaning. It may well be the best theory of meaning anyone has come up with, since meaning being out in the world strikes me as absurd.

15.06.01	p.53	23500	My main problem is the order of the world, and whether it is knowable a priori
			Full Idea: The great problem around which everything turns that I write is: is there an order in the world a priori, and if so what does it consist in?
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 15.06.01)
			A reaction: Morris identifies this as a 'Kantian question'. I trace it back to stoicism. This question has never bothered me. It just seems weird to think that you can infer reality from the examination of your own thinking. Perhaps I should take it more seriously?

1916. 2 Sep	p.379	22323	The philosophical I is the metaphysical subject, the limit - not a part of the world
			Full Idea: The philosophical I is not the man, not the human body, or the human soul of wh9ch psychology treats, but the metaphysical subject, the limit - not a part of the world.
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 1916. 2 Sep), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 58 Intro
			A reaction: This is to treat the self as a phenomenon of thought, rather than of a human being. So if a machine could think, would it hence necessarily have a metaphysical self?

23e	p.23	18276	A statement's logical form derives entirely from its constituents
			Full Idea: The logical form of the statement must already be given in the forms of its constituents.
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 23e)
			A reaction: This would evidently require each constituent to have a 'logical form'. It is hard to see what that could beyond its part of speech. Do two common nouns have the same logical form?

4	p.973	16908	We can dispense with self-evidence, if language itself prevents logical mistakes
			Full Idea: The 'self-evidence' of which Russell talks so much can only be dispensed with in logic if language itself prevents any logical mistake.
			From: comment on Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 4) by Robin Jeshion - Frege's Notion of Self-Evidence 4
			A reaction: Jeshion presents this as a key idea, turning against Frege, and is the real source of the 'linguistic turn' in philosophy. If self-evidence is abandoned, then language itself is the guide to truth, so study language. I think I prefer Frege. See Quine?

46e	p.46	18274	Analysis complicates a statement, but only as far as the complexity of its meaning
			Full Idea: Analysis makes the statement more complicated than it was; but it cannot and ought not to make it more complicated than its meaning (Bedeutung) was to begin with. When the statement is as complex as its meaning, then it is completely analysed.
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], 46e)
			A reaction: But how do you assess how complex the 'Bedeutung' was before you started?

end	p.171	4678	Absolute prohibitions are the essence of ethics, and suicide is the most obvious example
			Full Idea: If suicide is allowed, then everything is allowed. If anything is not allowed, then suicide is not allowed. This throws a light on the nature of ethics, for suicide is, so to speak, the elementary sin.
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], end), quoted by Jonathan Glover - Causing Death and Saving Lives §13
			A reaction: This reveals the religious streak in Wittgenstein. I am reluctant to judge suicide, but this seems wrong. Should a 'jumper' worry if they land on someone else and kill them? Of course they should.

p.14c	p.14	23472	The sense of propositions relies on the world's basic logical structure
			Full Idea: In order for a proposition to be CAPABLE of making sense, the world must already have the logical structure it has. The logic of the world is prior to all truth and falsehood.
			From: Ludwig Wittgenstein (Notebooks 1914-1916 [1915], p.14c)
			A reaction: It seems that in Tractatus it is propositions about facts which are true or false, but prior to the facts are substance and the objects, and it is there that we find the logical structure of the world. I see this view as modern stoicism.

1919	Letters to Russell

	p.18	7085	The main problem of philosophy is what can and cannot be thought and expressed
			Full Idea: The 'Tractatus' concerns the theory of what can be expressed by propositions (and, which comes to the same thing, can be thought), and what cannot be expressed by propositions, but can only be shown; which, I believe, is the main problem of philosophy.
			From: report of Ludwig Wittgenstein (Letters to Russell [1919]) by A.C. Grayling - Wittgenstein Ch.2
			A reaction: This contains what a I consider the heresy of making thought depend on language, but his main question remains, of the limits of thought. It is dramatised nicely in the 'mysterian' view of the mind-body problem (e.g. Idea 2540).

CL 125	p.32	23463	Atomic facts correspond to true elementary propositions
			Full Idea: Atomic fact [Sachverhalt] is what corresponds to an elementary proposition [Elementarsatz] if it is true.
			From: Ludwig Wittgenstein (Letters to Russell [1919], CL 125)
			A reaction: This is perhaps the key to the Tractatus, because it is the binding point between world and language. A true realist would allow for atomic facts that may go beyond even possible propositions.

p.125	p.157	23490	A thought is mental constituents that relate to reality as words do
			Full Idea: Does a Gedanke [thought] consist of words? No! But of psychical constituents that have the same sort of relation to reality as words.
			From: Ludwig Wittgenstein (Letters to Russell [1919], p.125), quoted by Michael Morris - Guidebook to Wittgenstein's Tractatus 4B
			A reaction: This is roughly my view of propositions, as non-lingustic mental events. The 'psychical constituents' seem to be concepts, in a psychological rather than a Fregean sense. This idea allowed transfer of his representation theory from thought to language.

1921	Tractatus Logico-Philosophicus

	p.6	7537	Wittgenstein convinced Russell that logic is tautologies, not Platonic forms
			Full Idea: Russell took a Platonist view of logic, but reading the 'Tractatus' convinced him that logic was purely linguistic, so-called 'logical truths' being nothing more than tautologies.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ray Monk - Bertrand Russell: Spirit of Solitude Ch.1
			A reaction: If p-and-q and p-or-q are both tautologies, how do you explain the difference between them? The first is an indicative proposition about the actual world, but the second is modal. They are asserting very different things.

	p.8	17665	The 'Tractatus' is instrumentalist about laws of nature
			Full Idea: Wittgenstein is an instrumentalist about laws of nature in 'Tractatus'.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by David M. Armstrong - What is a Law of Nature? 01.3
			A reaction: [I record this, but don't know the reference]

	p.12	6849	Wittgenstein hated logicism, and described it as a cancerous growth
			Full Idea: Wittgenstein didn't just have an arguments against logicism; he hated logicism, and described is as a cancerous growth.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ray Monk - Interview with Baggini and Stangroom p.12
			A reaction: This appears to have been part of an inexplicable personal antipathy towards Russell. Wittgenstein appears to have developed a dislike of all reductionist ideas in philosophy.

	p.14	10967	Wittgenstein's picture theory is the best version of the correspondence theory of truth
			Full Idea: Wittgenstein's picture theory is without doubt the best thought-out and developed of all the versions of the correspondence theory of truth.
			From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Stephen Read - Thinking About Logic Ch.1

	p.16	9810	The 'Tractatus' is a masterpiece of anti-philosophy
			Full Idea: The 'Tractatus' is without doubt one of the masterpieces of anti-philosophy.
			From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Alain Badiou - Mathematics and Philosophy: grand and little p.16
			A reaction: French philosophers do love making wicked remarks like that. It seems that analysis is anti-philosophy, or 'little' philosophy in Badiou's parlance.

	p.18	7084	What can be said is what can be thought, so language shows the limits of thought
			Full Idea: In Wittgenstein's view, what can be said is the same as what can be thought; so that once one has grasped the nature of language, one has shown the limit beyond which language and thought become nonsense.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2
			A reaction: I just don't believe that what is thinkable is limited to what is expressible. A lot of philosophy is the struggle to find expression for thoughts which are just beyond the edge of current language. See Idea 6870.

	p.35	18349	All truths have truth-makers, but only atomic truths correspond to them
			Full Idea: In 1922 Wittgenstein said that every truth has a truth-maker, but only atomic truths correspond to their truth-makers.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Adolph Rami - Introduction: Truth and Truth-Making note 04
			A reaction: Presumably this is what logical atomism is meant to be (cf Russell). The atomic sentences plug into the world, and the rest are constructions from them, making the latter more remote from the truth-makers.

	p.36	7087	Language is [propositions-elementary propositions-names]; reality is [facts-states of affairs-objects]
			Full Idea: Language consists in propositions, which are made of 'elementary' propositions, which are based ultimately on names. This matches the world of facts, compounded out of 'states of affairs', which are compounded of objects.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2
			A reaction: This is Grayling's summary of the basic idea of the 'Tractatus'. The whole thing seems to be an elaborate version of Russell's 'congruence' account of the correspondence theory of truth. Later Wittgenstein is loss of faith in this theory.

	p.38	7088	Logic and maths can't say anything about the world, since, as tautologies, they are consistent with all realities
			Full Idea: Neither logical nor mathematical propositions say anything about the world, because in virtue of their always being true they are consistent with any way the world could happen to be.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2
			A reaction: This became the standard view for twentieth century empiricists, and appeared to rule out a priori synthetic knowledge forever. Kripke's proposal that there are a posteriori necessities, however, changes the picture.

	p.39	4702	The account of truth in the 'Tractatus' seems a perfect example of the correspondence theory
			Full Idea: Wittgenstein's account in the 'Tractatus' is often taken as a paradigm instance of a sophisticated correspondence theory of truth.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Paul O'Grady - Relativism Ch.2
			A reaction: This might explain why I am so much more drawn to the 'Tractatus' than to the later relativistic anti-philosophical mind-eliminitavist, meaning-eliminativist Wittgenstein.

	p.66	23507	Unlike the modern view of a set of worlds, Wittgenstein thinks of a structured manifold of them
			Full Idea: In 'Tractatus' Wittgenstein is not just thinking of a set of possible worlds (in the modern account), but of a structured manifold within which each 'possible world' is located.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Roger M. White - Wittgenstein's 'Tractatus Logico-Philosophicus' 3 'Positions'
			A reaction: So the modern view has the neutrality of a merely formal system, but LW is thinking of them as the modal structure of reality.

	p.71	7090	The 'Tractatus' is an extreme example of 'Logical Atomism'
			Full Idea: The 'Tractatus' is an uncompromising, indeed an extreme, example of 'Logical Atomism'
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by A.C. Grayling - Wittgenstein Ch.2
			A reaction: Russell talked about his 'logical atomism' after 1918, but this reminds us that Wittgenstein was fulfilling a task set for him by Russell. Wittgenstein's atoms are names-plus-objects, Russell's are demonstratives-plus-sensedata.

	p.74	10910	The best account of truth-making is isomorphism
			Full Idea: The most sophisticated account of truth-making to have appeared to date is the 'isomorphism' theory of the Tractatus.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Mulligan/Simons/Smith - Truth-makers §5
			A reaction: Wittgenstein's theory is clearly closely related to Russell's 'congruence' theory of correspondence of around 1912.

	p.88	6428	Wittgenstein is right that logic is just tautologies
			Full Idea: I think Wittgenstein is right when he says (in the 'Tractatus') that logic consists wholly of tautologies.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Bertrand Russell - My Philosophical Development Ch.10
			A reaction: Despite Russell's support, I find this hard to accept. While a 'pure' or 'Platonist' logic may be hard to demonstrate or believe, I have a strong gut feeling that logic is more of a natural phenomenon than a human convention.

	p.113	23479	The Tractatus aims to reveal the necessities, without appealing to synthetic a priori truths
			Full Idea: We can see the 'Tractatus' as an attempt to make sense of what is necessarily true of the world - in general, and not just in the mathematical case - without appealing to synthetic a priori truths.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Michael Morris - Guidebook to Wittgenstein's Tractatus 2H
			A reaction: Morris sees the Tractatus as firmly in the Kantian tradition, and exploring Kant's main project in the first Critique.

	p.143	9467	Wittgenstein tried unsuccessfully to reduce quantifiers to conjunctions and disjunctions
			Full Idea: Wittgenstein reduces the universal quantifier to conjunctions of singular predications, and the existential quantifier to disjunctions of singular predications. ..This is nowadays understood as a failed effort.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Dale Jacquette - Intro to III: Quantifiers p.143
			A reaction: The problem this meets has something to do with infinite objects. In a domain of three objects it looks like a perfectly plausible strategy. 'All' is all three, and 'Some' is at least one of the three.

	p.194	13429	The identity sign is not essential in logical notation, if every sign has a different meaning
			Full Idea: Wittgenstein discovered that the sign of identity is not a necessary constituent of logical notation, but can be replaced by the convention that different signs must have different meanings.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Frank P. Ramsey - The Foundations of Mathematics p.139
			A reaction: [Ramsey cites p.139 - need to track down the modern reference] Hence in modern logic it is usually necessary to say that we are using 'classical logic with identity', since the use of identity is very convenient, and reasonably harmless (I think).

	p.228	13830	Logical truths are just 'by-products' of the introduction rules for logical constants
			Full Idea: Wittgenstein's by-product theory is that the meanings of the logical constants are conveyed by their introduction rules, and these rules have as a by-product the class of logical truths.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by Ian Hacking - What is Logic? §03
			A reaction: I find this approach highly plausible. All the truths about chess openings are just a by-product of the original rules.

	p.286	18154	The sign of identity is not allowed in 'Tractatus'
			Full Idea: The 'Tractatus' does not allow the introduction of a sign for identity.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921]) by David Bostock - Philosophy of Mathematics 9.B.4

Pref	p.3	23499	This book says we should either say it clearly, or shut up
			Full Idea: The whole sense of the book might be summed up in the following words: what can be said at all can be said clearly, and what we cannot talk about we must pass over in silence.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], Pref)
			A reaction: This also provides the last sentence of his book. I think this is an axiom of modern analytic philosophy. The dream is to clarify everything, and belief that this is possible puts logic centre-stage, as the most precise language available.

Pref	p.4	23459	This work solves all the main problems, but that has little value
			Full Idea: I believe myself to have found, on all essential points, the final solution of the problems. ….and this work shows how little is achieved when these problems are solved.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], Pref)
			A reaction: This is LW's deep pessimism about the value of philosophy, right from the start. You can only idolise LW if you agree with him on this.

1 - 1.2	p.5	13133	The world is facts, not things. Facts determine the world, and the world divides into facts
			Full Idea: The world is the totality of facts, not of things. The world is determined by the facts, and by their being all the facts. The totality of facts determines what is the case, and what is not the case. ..The world divides into facts.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1 - 1.2)
			A reaction: This is said to be a radical new ontology, because the facts are held to be prior to the things and their properties, which are presumably abstractions from the primitive facts. The modern heir of this is Armstrong's 'states of affairs'.

1.11	p.322	22311	The world is determined by the facts, and there are no further facts
			Full Idea: The world is determined by the facts, and by these being all the facts.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1.11), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 47 'Mole'
			A reaction: He is denying negative facts (also written to Russell in 1919). Best approached through truthmakers, I suspect. There is no truthmaker for the supposed factual claim 'there are birds on Mars' - so it is a fact that there are no birds on Mars.

1.12	p.27	23462	He says the world is the facts because it is the facts which fix all the truths
			Full Idea: Wittgenstein is thinking of the world as what makes truths true. …To get all the truths fixed we need more than the things: we need, as it were, the way things are - that is to say, the facts.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 1.12) by Michael Morris - Guidebook to Wittgenstein's Tractatus 1
			A reaction: Morris says this is 'sometimes suggested'. It strikes me as plausible, and makes LW a key source for the modern truthmaker idea. Perhaps in David Lewis's version of it. The facts include the relations and processes of the things.

2.0123	p.6	11027	To know an object you must know all its possible occurrences
			Full Idea: If I know an object I also know all its possible occurrences in states of affairs. (Every one of those possibilities must be part of the nature of the object.) A new possibility cannot be discovered later.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0123)
			A reaction: The requirement that you know them 'all' seems absurd, especially if we need science to discover them. I take this idea to be extremely important, and essentially Aristotelian (connecting with the notion of 'potentiality'). We need to know the powers.

2.01231	p.349	22321	To know an object we must know the form and content of its internal properties
			Full Idea: Wittgenstein explicitly said that to know an object I must know all its internal properties. ...Internal properties have form and content; form is 'possibility of occurrence in atomic facts' (2.0141), content is its being that specific object (2.0233).
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.01231) by Michael Potter - The Rise of Analytic Philosophy 1879-1930 52 'Simp'
			A reaction: [check original quote] This seems to be an essentialist view of (formal) objects. See Potter 347-9 for discussion. The 'external properties' of an object are the atomic facts in which it occurs.

2.013	p.6	23470	Each thing is in a space of possible facts
			Full Idea: Each thing is, as it were, in a space of possible states of affairs. This space I can imagine as empty, but not of the thing without the space.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.013)
			A reaction: A clear echo of Kant on natural space. LW calls it 'logical space' (1.13). I take this to be exactly the concept of the space of possibilities which contains the modern notion of possible worlds.

2.0141	p.6	23465	The 'form' of an object is its possible roles in facts
			Full Idea: The possibility of its occurrence in atomic facts is the form of the object.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0141)
			A reaction: Morris says this picks up the idea from Kant. We might now label the 'form' as the 'modal profile' of the object (a phrase I like). The modern issues over transworld identity seem to be a development of this thought.

2.02	p.7	23467	Objects are simple
			Full Idea: Objects are simple
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.02)
			A reaction: Presumably all his objects are 'simples', and what we think of as normal objects are counted by LW as 'facts'.

2.0201	p.7	6429	All complex statements can be resolved into constituents and descriptions
			Full Idea: Every statement about complexes can be resolved into a statement about their constituents and into the propositions that describe the complexes completely.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0201)
			A reaction: Russell says this embodies Wittgenstein's belief in analysis. Obviously Wittgenstein is making this claim 'in principle', as life is very short, and people are rather dim. I don't know how to begin evaluating such a claim.

2.021	p.7	23466	Objects are the substance of the world
			Full Idea: Objects make up the substance of the world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.021)
			A reaction: He doesn't say here that the objects are physical, and may be including Frege's abstract objects. His concept of substance seems more like Spinoza than Aristotle.

2.022	p.7	23469	An imagined world must have something in common with the real world
			Full Idea: It is obvious that an imagined world, however different it may be from the real one, must have something - a form - in common with it.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.022)
			A reaction: It is clear that Wittgenstein had a concept of possible worlds close to the modern view.

2.0233	p.7	12869	Two objects may only differ in being different
			Full Idea: If two objects have the same logical form, the only distinction between them, apart from their external properties, is that they are different.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.0233)
			A reaction: This isn't a commitment to haecceities, but it seems to be flirting with the idea. See Simons 1987:241. Kit Fine picks up the idea that objects, as well as sentences, might have 'logical form'. How can being 'different' be primitive? Spatial location?

2.024	p.7	23468	Apart from the facts, there is only substance
			Full Idea: Substance is what remains independently of what is the case.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.024)
			A reaction: He sees what is the case as comprised of objects, so substance is even more basic. It seems close to Spinoza's single-substance view.

2.03	p.8	23464	In atomic facts the objects hang together like chain links
			Full Idea: In an atomic fact [Sachverhalt] the objects hang one in another, like the links of a chain
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.03), quoted by Homer - The Iliad
			A reaction: So the world consists of facts, but the facts are composed of objects. The point seems to be that the truths of language refer to the facts, rather than to the objects. Objects 'don't hang' together in the fact of a chance encounter.

2.032-3	p.8	23471	The structure of an atomic fact is how its objects combine; this possibility is its form
			Full Idea: The way in which objects hang together in the atomic fact is the structure of the atomic fact. …The form is the possibility of the structure.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.032-3)
			A reaction: I very much like the way LW adds a modal dimension to his ontology. Why doesn't he talk of 'relations', rather than 'hanging together'?

2.04	p.53	23473	Do his existent facts constitute the world, or determine the world?
			Full Idea: Wittgenstein's writing here is loose, and he seems to be conflating two claims: 1) The totality of existent facts is the world (everything that is the case), and 2) The totality of existent facts determines everything that is the case (the world).
			From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.04) by Michael Morris - Guidebook to Wittgenstein's Tractatus 1E
			A reaction: [Also 2.06 and 2.063] Morris says he must actually mean the second version.

2.06	p.322	22313	The existence of atomic facts is a positive fact, their non-existence a negative fact
			Full Idea: The existence of atomic facts we also call a positive fact, their non-existence a negative fact. b...The existence and non-existence of atomic facts is the reality. ...[2.063] the total reality is the world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.06), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 47 'Mole'
			A reaction: Potter observes that he denies negative facts in a1919 letter to Russell, and at 1.11, but then affirms them at 2.06.

2.151	p.9	23482	The 'form' of the picture is its possible combinations
			Full Idea: The form of depiction is the possibility that the things are combined with one another as are the elements of the picture.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.151)
			A reaction: This is why 'model' (or even 'simulation'?) is a better term than 'picture' for his proposal. Pictures are fixed, but models can be adjusted.

2.1511-5	p.9	7056	Pictures reach out to or feel reality, touching at the edges, correlating in its parts
			Full Idea: A picture attaches to reality by reaching out to it; it is laid against reality like a measure; only the end-points actually touch the object; the pictorial relationship consists of correlations of picture's elements with things, the picture's feelers.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.1511-5)
			A reaction: (somewhat compressed). This is Wittgenstein's so-called 'picture theory' of meaning (replaced later by 'meaning is use'). It is perhaps better seen as an account of the correspondence theory of truth. Compare Russell's 'congruence' view (Idea 5427).

2.15121	p.129	23483	Proposition elements correlate with objects, but the whole picture does not correspond to a fact
			Full Idea: Correlation need only be between elements of the picture and things in reality; it is not also required that there be a correspondence between the picture as a whole and a fact in reality - so things can be depicted falsely.
			From: report of Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.15121) by Michael Morris - Guidebook to Wittgenstein's Tractatus 3C
			A reaction: To turn his picture theory into a correspondence theory of truth would need a further step, of saying the proposition is true when the two structures coincide. I don't think LW says that.

2.202	p.10	23486	Pictures are possible situations in logical space
			Full Idea: A picture represents a possible situation in logical space.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.202)
			A reaction: This seems pretty close to the idea that propositions are sets of possible worlds (though that seems to add unnecessary extra baggage). If they just picture situations, why does he mention logical space? Within the limits of possible picturing?

2.225	p.10	23485	No pictures are true a priori
			Full Idea: There are no pictures that are true a priori.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 2.225)
			A reaction: This is part of the growing modern doubts about the scope or possibility of a priori knowledge. A 'picture' here is the mental model which is the meaning of a proposition.

3.02	p.11	23487	What is thinkable is possible
			Full Idea: What is thinkable is possible too.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.02)
			A reaction: [Plucked from a context!] The modern tide has turned against this idea. The more clearly you understand the facts, the more restricted the possibilities become. If you think the impossible is possible, it is because you are bad at thinking.

3.203/3.26	p.12	7089	A name is primitive, and its meaning is the object
			Full Idea: A name means an object; an object is its meaning. ...A name cannot be dissected further by means of a definition: it is a primitive sign.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.203/3.26)
			A reaction: This is the optimistic view of names, that they are the point at which language plugs into the world (Russell preferred demonstratives for that job). Kripke's baptismal view of names has the same aspiration.

3.26	p.13	23506	Names are primitive, and cannot be analysed
			Full Idea: A name cannot be dissected any further by means of a definition: it is a primitive sign.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.26)
			A reaction: All logicians and analytic philosophers seem to agree on this. He means terms which pick out specific objects.

3.328	p.16	2939	If a sign is useless it is meaningless; that is the point of Ockham's maxim
			Full Idea: If a sign is useless it is meaningless. That is the point of Occam's maxim.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 3.328)

4.002	p.19	23492	Our language is an aspect of biology, and so its inner logic is opaque
			Full Idea: Everyday language is a part of the human organism and is no less complicated than it. It is not humanly possible to gather immediately from it what the logic of language is.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.002)
			A reaction: It is normally assumed that ordinary language philosophy was derived from the later Wittgenstein, but this para in the Tractatus seems to contain the germ of the idea. He is pessimistic about finding logical forms.

4.003	p.19	23510	Most philosophical questions arise from failing to understand the logic of language
			Full Idea: Most of the propositions and questions of philosophers arise from our failure to understand the logic of our language.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.003)
			A reaction: I'm not sure what the scope of 'logic' is here. I suppose it means everything about language which is expounded in the Tractatus. I assume this includes Plato and Aristotle? I don't think I agree. It's about concepts, not about logic.

4.0031	p.109	18268	Apparent logical form may not be real logical form
			Full Idea: The apparent logical form of the proposition need not be its real logical form.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.0031), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 6 'The incom'
			A reaction: This is one of the key doctrines of modern analytic philosophy.

4.024	p.21	23488	Propositions are understood via their constituents
			Full Idea: A proposition is understood by anyone who understands its constituents.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.024)
			A reaction: The 'constituents' had better include the grammatical relationships. Otherwise it's 'rearrange these words to make a well known saying'. That said, this strikes me as an important truth about language. We assemble sentence meanings.

4.024	p.21	8172	To understand a proposition means to know what is the case if it is true
			Full Idea: To understand a proposition means to know what is the case if it is true.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.024)
			A reaction: This established the Frege truth-conditions theory of meaning, which was expanded by Davidson, and then possible worlds semantics. You can't assess truth without knowing meaning. Dummett says the two go together.

4.025	p.21	23489	We translate by means of proposition constituents, not by whole propositions
			Full Idea: When translating one language into another, we do not proceed by translating each proposition of the one into a proposition of the other, but merely by translating the constituents of propositions.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.025)
			A reaction: This seems opposed to Quine's later holistic view of translating whole languages. Is he objecting to Frege's context principle?

4.03	p.22	23511	Propositions use old expressions for a new sense
			Full Idea: A proposition must use old expressions to communicate a new sense.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.03)
			A reaction: A nicely expressed affirmation of the principle of compositionality. It entails that the propositions can be either true or false, according to LW.

4.0312	p.22	10905	My fundamental idea is that the 'logical constants' do not represent
			Full Idea: My fundamental idea is that the 'logical constants' do not represent; that the logic of facts does not allow of representation.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.0312)
			A reaction: This seems to a firm rebuttal of any sort of platonism about logic, and implies a purely formal account.

4.063	p.55	22314	On white paper a black spot is a positive fact and a white spot a negative fact
			Full Idea: On white paper, the fact that a point is black corresponds to a positive fact; to the fact that a point is white (not black), a negative fact.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.063), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 08 'Judg'
			A reaction: Elsewhere Wittgenstein is ambiguous as to whether he believes in negative facts [qv].

4.11	p.25	23508	Science is all the true propositions
			Full Idea: The totality of true propositions is the whole of natural science (or the whole corpus of the natural sciences).
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.11)
			A reaction: So if it is true, it is science. What about truths about science? What about true speculations beyond science? What about bad science? What about trivial everyday truths? This is said to be a rare precursor of logical positivism in Tractatus.

4.123	p.27	7968	A relation is internal if it is unthinkable that its object should not possess it
			Full Idea: A relation is internal if it is unthinkable that its object should not possess it. (This shade of blue and that one stand, eo ipso, in the internal relation of lighter to darker. It is unthinkable that these two objects should not stand in this relation).
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.123)
			A reaction: An epistemological definition. If only one shade of blue existed, would it still have this internal relation? Are things therefore full of potential internal relations with non-existent things?

4.1252	p.27	7969	The order of numbers is an internal relation, not an external one
			Full Idea: The order of the number-series is not governed by an external relation but by an internal relation.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.1252)
			A reaction: He seems to mean something like a tautology (see Idea 7968). It is, I take it, part of the concept of any given integer that it has a place in the series. But do the concepts arise self-evidently, or from nature?

4.1272	p.29	7784	'Object' is a pseudo-concept, properly indicated in logic by the variable x
			Full Idea: The variable name ‘x’ is the proper sign of the pseudo-concept object. Wherever the word ‘object’ (‘thing’, ‘entity’, etc.) is rightly used, it is expressed in logical symbolism by the variable name.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.1272)
			A reaction: This seems to be the germ of Quine's famous dictum (Idea 1610). I am not persuaded that because logic must handle an object as a variable, that it follows that we are dealing with a pseudo-concept. Let logic limp behind life.

4.211	p.89	21682	If a proposition is elementary, no other elementary proposition contradicts it
			Full Idea: It is a sign of a proposition's being elementary that there can be no elementary proposition contradicting it.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.211)
			A reaction: It is a hallmark of atomic atoms that they have no relations with other atoms, but are wholly independent. This obviously invites the question of how they are united. Are logical connectives intrinsically relational logical atoms?

4.221	p.337	22319	Analysis must end in elementary propositions, which are combinations of names
			Full Idea: It is obvious that in the analysis of propositions we must come to elementary propositions, which consist of names in immediate combination.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 4.221), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 50 'Indep'
			A reaction: Not clear about 'combinations of names'. Does that include predicates? How do you combine two names?

5.132	p.39	18277	If q implies p, that is justified by q and p, not by some 'laws' of inference
			Full Idea: If p follows from q, I can make an inference from q to p, deduce p from q. The nature of the inference can be gathered only from the two propositions. They are the only possible justification of the inference. 'Laws of Inference' would be superfluous.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.132)
			A reaction: That seems to imply that each inference is judged on its particulars. But logic aims to be general. There seem to be 'laws' at a more complex level in the logic.

5.134	p.109	21683	Nothing can be inferred from an elementary proposition
			Full Idea: From an elementary proposition no other can be inferred.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.134)
			A reaction: Russell was not so sure. This is the sort of remark that elicits from me the question that extravagent metaphysics also provokes - 'how on earth does he know what he claims to be true?'.

5.1363	p.972	16907	If the truth doesn't follow from self-evidence, then self-evidence cannot justify a truth
			Full Idea: If the truth of a proposition does not follow from the fact that it is self-evident to us, then its self-evidence in no way justifies our belief in its truth.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.1363), quoted by Robin Jeshion - Frege's Notion of Self-Evidence 4
			A reaction: Frege seems to have taken self-evidence as intrinsic justification, but Wittgenstein seems to demand a supporting inference. But what is it all based on? Stipulative definitions?

5.44	p.45	23493	'Not' isn't an object, because not-not-p would then differ from p
			Full Idea: If there were an object called 'not', it would follow that 'not-not-p' would say something different from what 'p' said, just because the one proposition would then be about 'not', and the other would not.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.44)
			A reaction: That is, the first proposition would be about not-p, and the second would be about p. Assuming we can say what such things are 'about'. A rather good argument that the connectives are not entities. P and double-negated P should be indistinguishable.

5.4731	p.47	11062	Logic is a priori because it is impossible to think illogically
			Full Idea: What makes logic a priori is the impossibility of illogical thought.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.4731)
			A reaction: That places the a priori aspect of it in us (in the epistemology), rather than in the necessity of the logic (the ontology), which is as Kripke says it should be.

5.4731	p.973	16909	Logic is a priori because we cannot think illogically
			Full Idea: That logic is a priori consists in the fact that we cannot think illogically.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.4731), quoted by Robin Jeshion - Frege's Notion of Self-Evidence 4
			A reaction: A rather startling claim. Presumably we have to say that when we draw a stupid inference, then we weren't really 'thinking'?

5.5301	p.52	6056	Identity is not a relation between objects
			Full Idea: It is self-evident that identity is not a relation between objects.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5301)
			A reaction: Part of Wittgenstein's claim that identity statements are 'pseudo-propositions'. See, in reply, the ideas of McGinn on identity. This was part of the drive that led to the extremes of logical positivism, killing metaphysics for two generations.

5.5302	p.358	22322	You can't define identity by same predicates, because two objects with same predicates is assertable
			Full Idea: Russell's definition of identity [x is y if any predicate of x is a predicate of y] won't do, because then one cannot say that two objects have all their properties in common
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5302), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 53 'Ident'
			A reaction: [The Russell is in Principia] Good. Even if Leibniz is right that no two obejcts have identical properties, it is at least meaningful to consider the possibility. Russell makes it an impossibility, rather than a contingent fact.

5.5303	p.52	6057	Two things can't be identical, and self-identity is an empty concept
			Full Idea: Roughly speaking, to say of two things that they are identical is nonsense, and to say of one thing that it is identical with itself is to say nothing at all.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5303)
			A reaction: Wittgenstein's attack on identity. It is best (following McGinn) to only speak of resemblance between two things (possibly to a very high degree, as in two electrons). Self-identity just is identity; you can drop the word 'identity', but not the concept.

5.5421	p.54	23498	The modern idea of the subjective soul is composite, and impossible
			Full Idea: Therre is no such thing as the soul - the subject, etc. - as it is conceived in the superficial psychology of the present day. Indeed a composite soul would no longer be a soul.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5421)
			A reaction: This seems to endorse Descartes' claim about the essential unity of the mind. I think Hume is in the background of LW's thought. Presumably the psychologist offered a 'composite' view. Prior discussion of belief leads into this remark.

5.5422	p.54	23475	The form of a proposition must show why nonsense is unjudgeable
			Full Idea: The correct explanation of the form of the proposition 'A judges p' must show that it is impossible to judge a nonsense. (Russell's theory does not satisfy this condition).
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.5422)
			A reaction: In Notebooks p.96 LW gives the example 'this table penholders the book'. I take it Russell wanted judgement to impose unified meaning on sentences, but LW shows that assembling meaning must precede judgement. LW is right.

5.6	p.56	2938	The limits of my language means the limits of my world
			Full Idea: The limits of my language means the limits of my world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.6)
			A reaction: This is dangerous rubbish. For a start, if you accept (as you should) the existence of propositions, our heads are full of unarticulated ones. And truth emerges by degrees from what cannot be articulated.

5.61	p.56	23502	Logic fills the world, to its limits
			Full Idea: Logic pervades the world: the limits of the world are also its limits.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.61)
			A reaction: This is a gospel belief for hardcore analytic philosophy. Hence Williamson writes a book on modal logic as metaphysics.

5.62	p.57	23497	Solipsism is correct, but can only be shown, not said, by the limits of my personal language
			Full Idea: What the solipsist means is quite correct; only it cannot be said, but makes itself manifest. The world is my world: this is manifest in the fact that the limits of language (of that language which I alone understand) mean the limits of my world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.62)
			A reaction: I take it that LW later showed that the remark in brackets is absurd, using his Private Language argument. Commentators seem unclear about how seriously to take this claim.

5.632	p.57	2940	The subject stands outside our understanding of the world
			Full Idea: The subject does not belong to the world; rather, it is a limit of the world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.632)
			A reaction: Interesting. We must not confuse epistemology with ontology, but the perceived world exists between two limits - the farthest reaches of my perceptions, and the farthest reaches of myself. I wish I could clearly disentangle the nearer border. Dasein?

5.634	p.58	23501	There is no a priori order of things
			Full Idea: Whatever we can describe at all could be other than it is. There is no a priori order of things.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.634)
			A reaction: This is his rejection of Kant's dream, of inferring truths about the world by self-examination. However, compare Idea 23495. He clings to the faith that logic reveals 'something' about reality.

5.64	p.58	23503	Strict solipsism is pure realism, with the self as a mere point in surrounding reality
			Full Idea: Solipsism, when its implications are followed out strictly, coincides with pure realism. The self of solipsism shrinks to a point without extension, and there remains the reality co-ordinated with it.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 5.64)
			A reaction: Despite this, Michael Morris is more inclined to see him as an idealist. It is not clear whether the present account of solipsism is idealist or realist. Berkeley seemed to think his idealism was true realism. Can reality be co-ordinated with a point?

6.021	p.59	18153	A number is a repeated operation
			Full Idea: A number is the index of an operation.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.021)
			A reaction: Roughly, this means that a number indicates how many times some basic operation has been performed. Bostock 2009:286 expounds the idea.

6.022	p.59	18160	The concept of number is just what all numbers have in common
			Full Idea: The concept of number is simply what is common to all numbers, the general form of number. The concept of number is the variable number.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.022)

6.031	p.59	18161	The theory of classes is superfluous in mathematics
			Full Idea: The theory of classes is completely superfluous in mathematics. This is connected with the fact that the generality required in mathematics is not accidental generality.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.031)
			A reaction: This fits Russell's no-class theory, which rests everything instead on propositional functions.

6.1	p.59	18162	The propositions of logic are analytic tautologies
			Full Idea: The propositions of logic are tautologies. Therefore the propositions of logic say nothing. (They are the analytic propositions).
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.1)

6.12	p.60	23495	The tautologies of logic show the logic of language and the world
			Full Idea: The fact that the propositions of logic are tautologies shows the formal - logical - properties of language and the world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.12)
			A reaction: This seems to me an extraordinarily hubristic remark (philosophically speaking), especially coming from a work which famously throws away its own ladder. He is very much pursuing Kant's project.

6.1262	p.64	15089	Logical proof just explicates complicated tautologies
			Full Idea: Proof in logic is merely a mechanical expedient to facilitate recognition of tautologies in complicated cases.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.1262)

6.127	p.64	19292	Logic doesn't split into primitive and derived propositions; they all have the same status
			Full Idea: All the propositions of logic are of equal status: it is not the case that some of them are essentially primitive propositions and others essentially derived propositions.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.127)
			A reaction: So axioms are conventional. This specifically contradicts the claims of Frege and the earlier Russell. Their view is that logic has an explanatory essence, found in some core axioms or rules or concepts. I agree with them.

6.22	p.65	23509	The logic of the world is shown by tautologies in logic, and by equations in mathematics
			Full Idea: The logic of the world, which is shown in tautologies by the propositions of logic, is shown in equations by mathematics.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.22)
			A reaction: White observes that this is Wittgenstein distinguishing logic from mathematics, and thus distancing himself from logicism. But see T 6.2.

6.3	p.67	23504	Logic concerns everything that is subject to law; the rest is accident
			Full Idea: The exploration of logic means the exploration of everything that is subject to law. And outside logic everything is accidental.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.3)
			A reaction: Why should laws be logical? Legislatures can pass whimsical laws. Does he mean that the laws of nature are logically necessary? He can't just mean logical laws.

6.363	p.70	2941	Induction accepts the simplest law that fits our experiences
			Full Idea: The procedure of induction consists in accepting as true the simplest law that can be reconciled with our experiences.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.363)

6.37	p.70	9442	The only necessity is logical necessity
			Full Idea: The only necessity that exists is logical necessity.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.37)
			A reaction: For Wittgenstein that will mean conventional necessity. He is taking a standard Humean view of these things.

6.371	p.70	17673	The modern worldview is based on the illusion that laws explain nature
			Full Idea: The whole modern conception of the world is founded on the illusion that the so-called laws of nature are the explanations of natural phenomena.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.371)
			A reaction: Love it! Not only does it say that lawlike explanation is wrong, but it registers that this is a profound feature of the modern view of the world, and not just a slightly misguided philosophical theory.

6.3751	p.71	23496	Two colours in the same place is ruled out by the logical structure of colour
			Full Idea: The simultaneous presence of two colours in the same place in the visual field is impossible, in fact logically impossible, since it is ruled out by the logical structure of colour.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.3751)
			A reaction: This sounds the wrong way around. We derive our concept of the logic of colour from experiencing the total incompatibility of two colours in the same location. What if each of our eyes saw a different colour?

6.41	p.71	2942	The sense of the world must lie outside the world
			Full Idea: The sense of the world must lie outside the world.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.41)
			A reaction: Since I don't believe that anything 'lies outside the world' I can't make sense of this. He implies that the Self lies outside of the world (to the point of solipsism), so I suppose that's it.

6.421	p.71	2943	Ethics cannot be put into words
			Full Idea: Ethics cannot be put into words.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.421)
			A reaction: Nonsense. There is lots of good writing about ethics. This is evasive mysticism.

6.5	p.73	2944	If a question can be framed at all, it is also possible to answer it
			Full Idea: If a question can be framed at all, it is also possible to answer it.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.5)
			A reaction: Just the sort of unsubstantiated metaphysical claim that philosophers are always making.

6.51	p.73	6591	Doubts can't exist if they are inexpressible or unanswerable
			Full Idea: Doubt can exist only where a question exists, a question only where an answer can exist, and an answer only where something can be said.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.51)
			A reaction: I don't agree with any of that. It is typical of the phase when philosophers were mesmerised by language. Cats look puzzled sometimes. A glimmering of doubt may be pre-linguistic, inexpressible and unanswerable, but still feels like a doubt.

6.53	p.73	7086	Good philosophy asserts science, and demonstrates the meaninglessness of metaphysics
			Full Idea: The correct method in philosophy would be to say nothing except what can be said, i.e. propositions of natural science, and whenever someone wanted to say something metaphysical, to show that he had failed to give a meaning to signs in his propositions.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.53)
			A reaction: This seems to be the germ of logical positivism, picked up by the Vienna Circle, and passed on the Ayer and co. How, though, do you 'show' that a sign is meaningless? Very abstract ideas are too far away from experience to be analysed that way.

6.54	p.74	23512	Once you understand my book you will see that it is nonsensical
			Full Idea: Anyone who understands me eventually recognises my propositions as nonsensical, when he has used them - as steps - to climb up beyond them. (He must, so to speak, throw away the ladder after he has climbed up it.)
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 6.54)
			A reaction: A much discussed passage. It can't possibly say that his book is pointless, because you can't attain this recognition without climbing his ladder. He speaks like an eastern guru. Perhaps Hume should have ended 'so commit my book to the flames'?

7	p.74	2937	What we cannot speak about we must pass over in silence
			Full Idea: What we cannot speak about we must pass over in silence.
			From: Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 7)
			A reaction: This is either a boring truism, or points towards some sort of verificationism (where we can speak meaninglessly). Compare Ideas 7973 and 6870.

7	p.267	6870	I say (contrary to Wittgenstein) that philosophy expresses what we thought we must be silent about
			Full Idea: I recognise the incredible force of Wittgenstein's closing statement in the 'Tractatus', but I hold the opposite view: philosophy exists to give expression to that which we think we can only remain silent about.
			From: comment on Ludwig Wittgenstein (Tractatus Logico-Philosophicus [1921], 7) by Keith Ansell Pearson - Interview with Baggini and Stangroom p.267
			A reaction: A wonderful remark, with which I totally agree. Compare Idea 1596. I think it is just a fact that philosophers are able to articulate a huge number of ideas which other intelligent people find very interesting but on which they are unable to speak.

1930	Philosophical Remarks

p.200	p.257	18282	You can't believe it if you can't imagine a verification for it
			Full Idea: It isn't possible to believe something for which you cannot imagine some kind of verification.
			From: Ludwig Wittgenstein (Philosophical Remarks [1930], p.200), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Constr'
			A reaction: In 1930 LW was calling this his 'old principle'. As it stands here it is too vague to assert very much.

p.72	p.348	22320	An 'object' is just what can be referred to without possible non-existence
			Full Idea: What I once called 'objects', simples, were simply what I could refer to without running the risk of their possible non-existence.
			From: Ludwig Wittgenstein (Philosophical Remarks [1930], p.72), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 52 'Simp'
			A reaction: For most of us, you can refer to something because you take it to be an object. For these Fregean influenced guys (e.g. Hale) something is an object because you can refer to it. Why don't they use 'object*' for their things?

p.85	p.326	18283	Language pictures the essence of the world
			Full Idea: The essence of language is a picture of the essence of the world.
			From: Ludwig Wittgenstein (Philosophical Remarks [1930], p.85), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 17
			A reaction: Hence for a long time the study of language seemed to be the way to do metaphysics. Now they study mathematical logic, with the same hope.

1931	Lectures 1930-32 (student notes)

A I.1	p.1	18704	Philosophy tries to be rid of certain intellectual puzzles, irrelevant to daily life
			Full Idea: Philosophy is the attempt to be rid of a particular kind of puzzlement. This 'philosophical' puzzlement is one of the intellect and not of instinct. Philosophical puzzles are irrelevant to our every-day life.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.1)
			A reaction: All enquiry begins with puzzles, and they are cured by explanations, which result in understanding. In that sense he is right. I entirely disagree that the puzzles are irrelevant to daily life.

A I.4	p.2	18705	Words function only in propositions, like levers in a machine
			Full Idea: Words function only in propositions, like the levers in a machine.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4)
			A reaction: Hm. Consider the word 'tree'. Did you manage to do it? Was it just a noise?

A I.4	p.3	18706	Words of the same kind can be substituted in a proposition without producing nonsense
			Full Idea: 'Blue' and 'brown' are of the same kind, for the substitution of one for the other, though it may falsify the proposition, does not make nonsense of it.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A I.4)
			A reaction: He chooses an easy example, because they are determinates of the determinable 'coloured'. What if I say 'the sky is blue', and then substitute 'frightening' for 'blue'?

A V.1	p.10	18707	All thought has the logical form of reality
			Full Idea: Thought must have the logical form of reality if it is to be thought at all.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A V.1)
			A reaction: This links nicely the idea that true thoughts somehow share the structure of what they refer to, with the idea of logical form in logic. But maybe logical form is a fiction we offer in order to obtain a spurious map of reality.

A VII.2	p.13	18708	Infinity is not a number, so doesn't say how many; it is the property of a law
			Full Idea: 'Infinite' is not an answer to the question 'How many?', since the infinite is not a number. ...Infinity is the property of a law, not of an extension.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A VII.2)

A XI.3	p.19	18709	Laws of logic are like laws of chess - if you change them, it's just a different game
			Full Idea: I might as well question the laws of logic as the laws of chess. If I change the rules it is a different game and there is an end of it.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], A XI.3)
			A reaction: No, that isn't the end of it, because there are meta-criteria for preferring one game to another. Why don't we just give up classical logic? It would be such fun to have a wild wacky logic. We can start with 'tonk'.

B Easter	p.62	18727	A person's name doesn't mean their body; bodies don't sit down, and their existence can be denied
			Full Idea: The meaning of the words 'Professor Moore' is not a certain human body, because we do not say that the meaning sits on the sofa, and the words occur in the proposition 'Professor Moore does not exist'.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B Easter)
			A reaction: Brilliant. Love it. Kripke ending up denying the existence of 'meanings'.

B I.1	p.22	18710	Philosophers express puzzlement, but don't clearly state the puzzle
			Full Idea: Philosophers as 'Why?' and 'What?' without knowing clearly what their questions are. They are expressing a feeling of mental uneasiness.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.1)
			A reaction: He suggests it is childish to express puzzlement, instead of asking for precise information. How odd. All enquiries start with vague puzzlement, which gradually comes into focus, or else is abandoned.

B I.2	p.22	18711	A proposition is any expression which can be significantly negated
			Full Idea: Any affirmation can be negated: if it has sense to say p it also has sense to say ¬p. ...A proposition therefore is any expression which can be significantly negated.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.2)
			A reaction: I'm not sure about 'therefore'. I'm thinking you would have to already grasp the proposition in order to apply his negation test.

B I.5	p.24	18712	Understanding is translation, into action or into other symbols
			Full Idea: Understanding is really translation, whether into other symbols or into action.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B I.5)
			A reaction: The second part of this sounds like pure pragmatism. To do is to understand? I doubt it. Do animals understand anything?

B II.4	p.27	18713	If an explanation is good, the symbol is used properly in the future
			Full Idea: The criterion of an explanation is whether the symbol explained is used properly in the future.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B II.4)
			A reaction: This appears to be a pragmatic criterion for the best explanation. It presumably rests on his doctrine that meaning is use, so good explanation is understanding meanings.

B IX.6	p.47	18719	Grammar says that saying 'sound is red' is not false, but nonsense
			Full Idea: If grammar says that you cannot say that a sound is red, it means not that it is false to say so but that it is nonsense - i.e. not a language at all.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B IX.6)
			A reaction: I am baffled as to why he thinks 'grammar' is what prohibits such a statement. Surely the world, the nature of sound and colour, is what makes the application of the predicate wrong. Sounds aren't coloured, so they can't be red. False, not nonsense.

B V.1	p.35	18714	We already know what we want to know, and analysis gives us no new facts
			Full Idea: In philosophy we know already all that we want to know; philosophical analysis does not give us any new facts.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B V.1)

B VI.2	p.37	18715	Using 'green' is a commitment to future usage of 'green'
			Full Idea: If I say this is green, I must say that other things are green too. I am committed to a future usage.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VI.2)
			A reaction: This seems to suggest that the eternal verity of a universal concept is just a convention of stability in a language.

B VII.2	p.40	18716	A machine strikes us as being a rule of movement
			Full Idea: We are accustomed to look on a machine as the expression of a rule of movement.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VII.2)
			A reaction: What a beautiful definition of a machine! I like this because it connects the two halves of my view of the 'essence' of a thing, as derived from Aristotle, as both a causal mechanism and an underlying principle. Cf Turing machines.

B VIII	p.42	18717	Thought is an activity which we perform by the expression of it
			Full Idea: Thought is an activity which we perform by the expression of it, and lasts as long as the expression.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII)
			A reaction: I take this to be an outmoded view of thought, which modern cognitive science has undermined, by showing how little of our thinking is actually conscious.

B VIII.2	p.43	18718	Saying 'and' has meaning is just saying it works in a sentence
			Full Idea: When we say that the word 'and' has meaning what we mean is that it works in a sentence and is not just a flourish.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B VIII.2)

B X.3	p.48	18720	Explanation gives understanding by revealing the full multiplicity of the thing
			Full Idea: An explanation gives understanding, ...but it cannot teach you understanding, it cannot create understanding. It makes further distinctions i.e. it increases multiplicity. When multiplicity is complete, then there is no further misunderstanding.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B X.3)
			A reaction: The thought seems to resemble Aristotle's idea of definition as gradual division of the subject. To understand is the dismantle the parts and lay them out before us. Wittgenstein was very interested in explanation at this time.

B XI.2	p.51	18721	Explanation and understanding are the same
			Full Idea: For us explanation and understanding are the same, understanding being the correlate of explanation.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XI.2)
			A reaction: I'm not convinced that they are 'the same', but they are almost interdependent ideas. Strevens has a nice paper on this.

B XII.1	p.53	18723	We may correctly use 'not' without making the rule explicit
			Full Idea: Correct use does not imply the ability to make the rules explicit. Understanding 'not' is like understanding a move in chess.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.1)

B XII.3	p.54	18724	In logic nothing is hidden
			Full Idea: In logic nothing is hidden.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XII.3)
			A reaction: If so, then the essence of logic must be there for all to see. The rules of natural deduction are a good shot at showing this.

B XIII.2	p.56	18725	A proposition draws a line around the facts which agree with it
			Full Idea: A proposition gives reality a degree of freedom; it draws a line round the facts which agree with it, and distinguishes them from those which do not.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIII.2)
			A reaction: This seems to be the idea of meaning as the range of truth conditions. Propositions as sets of possible worlds extends this into possible facts which agree with the proposition. Most facts neither agree nor disagree with some proposition.

B XIV.2	p.57	18726	For each necessity in the world there is an arbitrary rule of language
			Full Idea: To a necessity in the world there corresponds an arbitrary rule in language.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], B XIV.2)
			A reaction: This seems to be hardcore logical positivism, making all necessities arbitrary. Compare Quine on the number of planets.

C I	p.66	18728	The meaning of a proposition is the mode of its verification
			Full Idea: The meaning of a proposition is the mode of its verification (and two propositions cannot have the same verification).
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C I)
			A reaction: Does this mean that if two sentences have the same mode of verification, then they must be expressing the same proposition? I guess so.

C III	p.69	18729	Part of what we mean by stating the facts is the way we tend to experience them
			Full Idea: There is no need of a theory to reconcile what we know about sense data and what we believe about physical objects, because part of what we mean by saying that a penny is round is that we see it as elliptical in such and such conditions.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C III)
			A reaction: This is an interesting and cunning move to bridge the gap between our representations and reallity. We may surmise how a thing really is, but then be surprised by the sense-data we get from it.

C V A	p.74	18730	The history of philosophy only matters if the subject is a choice between rival theories
			Full Idea: If philosophy were a matter of choice between rival theories, then it would be sound to teach it historically. But if it is not, then it is a fault to teach it historically, because it is quite unnecessary; we can tackle the subject direct.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V A)
			A reaction: Wittgenstein was a bit notorious for not knowing the history of the subject terribly well, and this explains why. Presumably our tackling the subject direct will not have the dreadful consequence of producing yet another theory.

C V B	p.75	18731	There is no theory of truth, because it isn't a concept
			Full Idea: It is wrong to say that there is any one theory of truth, for truth is not a concept.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B)
			A reaction: This makes you wonder how he understood the word 'concept'. In most modern discussions truth seems to be a concept, and in Frege it can be an unsaturated predicate which is satisfied by sentences or thoughts.

C V B	p.76	18732	We don't need a theory of truth, because we use the word perfectly well
			Full Idea: It is nonsense to try to find a theory of truth, because we can see that in everyday life we use the word quite clearly and definitely in various different senses.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V B)
			A reaction: This was a year before Tarski published his famous theory of truth for formal languages. Prior to that, most philosophers were giving up on truth. Would he say the same about 'gravity' or 'inflation'?

C V C	p.79	18733	Laws of nature are an aspect of the phenomena, and are just our mode of description
			Full Idea: The laws of nature are not outside phenomena. They are part of language and of our way of describing things; you cannot discuss them apart from their physical manifestation.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C V C)
			A reaction: I suppose this amounts to a Humean regularity theory - that the descriptions pick out patterns in the manifestations. I like the initial claim that they are not external to phenomena.

C VII	p.83	18734	If you remember wrongly, then there must be some other criterion than your remembering
			Full Idea: If you remember wrongly, then there must be some other criterion than your remembering. If you admit another test, then your memory itself is not the test.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C VII)
			A reaction: If I fear that I am remembering some private solitary event wrongly, there is no other criterion to turn to, so I'm stuck. Sometimes dubious memories are all we have.

C X	p.87	18735	Talking nonsense is not following the rules
			Full Idea: Talking nonsense is not following the rules.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C X)
			A reaction: He doesn't seem to distinguish between syntax and semantics, and makes it sound as if all nonsense is syntactic, which it isn't.

C XIII	p.92	18736	Contradiction is between two rules, not between rule and reality
			Full Idea: Contradiction is between one rule and another, not between rule and reality.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII)
			A reaction: If I say 'he is sitting' and 'he is standing', it seems to be reality which produces the contradiction. What 'rule' could possibly do it? The rule which says sitting and standing are incompatible? But what makes that so?

C XIII	p.93	18737	There are no positive or negative facts; these are just the forms of propositions
			Full Idea: There are no positive or negative facts. 'Positive' and 'negative' refer to the form of propositions, and not to the facts which verify or falsify them.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], C XIII)
			A reaction: Personally I think if we are going to allow the world to be full of 'facts', then there are negative, conjunctive, disjunctive and hypothetical facts.

Notes	p.114	18738	We don't get 'nearer' to something by adding decimals to 1.1412... (root-2)
			Full Idea: We say we get nearer to root-2 by adding further figures after the decimal point: 1.1412.... This suggests there is something we can get nearer to, but the analogy is a false one.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], Notes)

p.82	p.245	18280	We live in sense-data, but talk about physical objects
			Full Idea: The world we live in is the world of sense-data, but the world we talk about is the world of physical objects.
			From: Ludwig Wittgenstein (Lectures 1930-32 (student notes) [1931], p.82), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Verif'
			A reaction: I really like that one. Even animals, I surmise, think of objects quite differently from the way they immediately experience them.

1932	Philosophical Grammar

§127	p.152	6606	Consider: "Imagine this butterfly exactly as it is, but ugly instead of beautiful"
			Full Idea: Suppose someone were to say: "Imagine this butterfly exactly as it is, but ugly instead of beautiful"?!
			From: Ludwig Wittgenstein (Philosophical Grammar [1932], §127), quoted by Robert Fogelin - Walking the Tightrope of Reason
			A reaction: This reminds us that the concept of supervenience was originally introduced in aesthetics. Beauty is supervenient on physical form. But "Imagine how someone else might look at this butterfly and think it was ugly".

p.468	p.255	18281	In mathematics everything is algorithm and nothing is meaning
			Full Idea: In mathematics everything is algorithm and nothing is meaning; even when it doesn't look like that because we seem to be using words to talk about mathematical things.
			From: Ludwig Wittgenstein (Philosophical Grammar [1932], p.468), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 13 'Constr'
			A reaction: I would have thought that an algorithm needs some raw material to work with. This leads to the idea that meaning arises from rules of usage.

1935

talk

	p.14	7536	If you hope to improve the world, all you can do is improve yourself
			Full Idea: When Wittgenstein was once asked what one can do to improve the world, he replied: 'Improve yourself; that is the only thing you can do to improve the world'.
			From: Ludwig Wittgenstein (talk [1935]), quoted by Ray Monk - Bertrand Russell: Ghost of Madness Ch.1
			A reaction: This is rather startlingly pessimistic about politics, and I don't really believe it. If anything has ever improved me, it has usually come from the world, and been created by other people.

1935

works

	p.40	10710	We accept substance, to avoid infinite backwards chains of meaning
			Full Idea: Wittgenstein is the most renowned modern proponent of substance, and argued that sense must be determinate ...and that any conceptual scheme which genuinely represents a world cannot contain infinite backward chains of meaning.
			From: report of Ludwig Wittgenstein (works [1935]) by Michael Potter - Set Theory and Its Philosophy 03.3
			A reaction: This is a key idea for explaining the somewhat surprising revival of the notion of substance in modern times, when it appeared to have been buried by atomism in the seventeenth century. The new argument is a semantic one.

1936	The Blue and Brown Notebooks

II.§16 n	p.77	6318	The doctrine of indeterminacy of translation seems implied by the later Wittgenstein
			Full Idea: Perhaps the doctrine of indeterminacy of translation will have little air of paradox for readers familiar with Wittgenstein's latter-day remarks on meaning.
			From: report of Ludwig Wittgenstein (The Blue and Brown Notebooks [1936], II.§16 n) by Willard Quine - Word and Object II.§16 n
			A reaction: This may be right, and I am inclined to link the names of Wittgenstein and Quine among those who led philosophy up a relativistic and sceptical cul-de-sac for many years. You can think too hard, you know.

pp. 66-7	p.48	22419	'I' is a subject in 'I am in pain' and an object in 'I am bleeding'
			Full Idea: 'I' is used as a subject in 'I am in pain', ....and used as an object in 'I am bleeding'.
			From: report of Ludwig Wittgenstein (The Blue and Brown Notebooks [1936], pp. 66-7) by Colin McGinn - Subjective View: sec qualities and indexicals 4
			A reaction: How about 'my wound is painful'? Does that have the logical form of a conversation? This idea is incorrect. Shoemaker (1968) suggests that the subjective use is immune to error, unlike the object use.

1938	Remarks on the Foundations of Mathematics

p.38	p.155	11073	Two and one making three has the necessity of logical inference
			Full Idea: "But doesn't it follow with logical necessity that you get two when you add one to one, and three when you add one to two? and isn't this inexorability the same as that of logical inference? - Yes! it is the same.
			From: Ludwig Wittgenstein (Remarks on the Foundations of Mathematics [1938], p.38), quoted by Robert Hanna - Rationality and Logic 6
			A reaction: This need not be a full commitment to logicism - only to the fact that the inferential procedures in mathematics are the same as those of logic. Mathematics could still have further non-logical ingredients. Indeed, I think it probably does.

p.38	p.155	11074	'It is true that this follows' means simply: this follows
			Full Idea: The proposition: "It is true that this follows from that" means simply: this follows from that.
			From: Ludwig Wittgenstein (Remarks on the Foundations of Mathematics [1938], p.38), quoted by Robert Hanna - Rationality and Logic 6
			A reaction: Presumably this remark is simply expressing Wittgenstein's later agreement with the well-known view of Ramsey. Early Wittgenstein had endorsed a correspondence view of truth.

1945	Culture and Value

53e	p.53	16010	While faith is a passion (as Kierkegaard says), wisdom is passionless
			Full Idea: Wisdom is passionless. But faith by contrast is what Kierkegaard calls a passion.
			From: Ludwig Wittgenstein (Culture and Value [1945], 53e)
			A reaction: [Idea from SY] Personally I don't agree that wisdom is passionless. At the very least, Aristotle allows the wise person to be appropriately angry. [PG]

1950

Zettel

§691	p.51	6569	'This sentence is false' sends us in a looping search for its proposition
			Full Idea: According to Wittgenstein, 'this sentence is false' sends us off on an endless, looping search for the proposition to be evaluated.
			From: report of Ludwig Wittgenstein (Zettel [1950], §691) by Robert Fogelin - Walking the Tightrope of Reason Ch.2
			A reaction: Fogelin quotes this as one possible strategy for dealing with the Liar Paradox. It doesn't sound like much of a solution to the paradox, merely an account of why it is so annoying. Wittgenstein's challenge is that the Cretan can't state his problem.

455	p.1	2626	A philosopher is outside any community of ideas
			Full Idea: The philosopher is not a citizen of any community of ideas; that is what makes him a philosopher.
			From: Ludwig Wittgenstein (Zettel [1950], 455)
			A reaction: A bit surprising from the man who gave us 'language games' and 'private language argument'.

i.437	p.27	3790	Causes of beliefs are irrelevant to their contents
			Full Idea: The causes of our belief in a proposition are indeed irrelevant to the question of what we believe.
			From: Ludwig Wittgenstein (Zettel [1950], i.437)
			A reaction: This should have nipped the causal theory of knowledge in the bud before it got started. Everyone has a different cause for their belief that 'it sometimes rains'. Cause is not justification.

1951	On Certainty

	p.159	3596	Total doubt can't even get started
			Full Idea: Wittgenstein remarked that if you tried to doubt everything, you would not get as far as doubting anything.
			From: report of Ludwig Wittgenstein (On Certainty [1951]) by Michael Williams - Problems of Knowledge Ch.14

§114	p.94	4721	If you are not certain of any fact, you cannot be certain of the meaning of your words either
			Full Idea: If you are not certain of any fact, you cannot be certain of the meaning of your words either.
			From: Ludwig Wittgenstein (On Certainty [1951], §114)
			A reaction: A wonderfully challenging aphorism. I suspect that it is true, but not really a problem. We all know the meaning of 'Loch Ness Monster', as long as we don't get too fussy. And for local objects I am happy that I know the facts.

§152	p.165	3597	Foundations need not precede other beliefs
			Full Idea: I do not explicitly learn the propositions that stand fast for me. I can discover them subsequently like the axis around which a body rotates.
			From: Ludwig Wittgenstein (On Certainty [1951], §152), quoted by Michael Williams - Problems of Knowledge Ch.14
			A reaction: A nice metaphor for the way in which axioms are derived. It is also close to Quine's metaphor of the 'net' of understanding, with the centre area 'standing fast'. Not neat and tidy, though.

1952	Philosophical Investigations

	p.12	23450	Wittgenstein rejected his earlier view that the form of language is the form of the world
			Full Idea: Wittgenstein's later work rejects the central thesis of the Tractatus's philosophy of language, that the form of language is the same as the form of the world.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by Michael Morris - Guidebook to Wittgenstein's Tractatus Intro.4
			A reaction: I associate the earlier view with the stoic belief that nature is wholly rational, and that our reasoning can match it. I take it for granted that language largely matches the world, but we must explain why so many people believe absurdities.

	p.14	12576	Possessing a concept is knowing how to go on
			Full Idea: Wittgenstein implies that which concepts a thinker is capable of possessing depends on the ways in which he is capable of finding a natural way to go on.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by Christopher Peacocke - A Study of Concepts 1.2
			A reaction: This doesn't seem to amount to much. Presumably someone who failed to grasp a concept would demonstrate the fact by going on in a silly way, and whether or not it was silly might not be obvious. A genius may go on in a quirky way.

	p.17	18743	Wittgenstein says we want the grammar of problems, not their first-order logical structure
			Full Idea: For the later Wittgenstein what we should be after is the grammatical structure of philosophical problems, not the first-order logical structure of such problems.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by Horsten,L/Pettigrew,R - Mathematical Methods in Philosophy 2
			A reaction: This is the most sympathetic spin I have ever seen put on the apparent rather anti-philosophical later Wittgenstein. I nurse doubts about highly formal approaches to philosophy, and maybe 'grammar' (whatever that is) is our target.

	p.43	6567	For Wittgenstein, words are defined by their use, just as chess pieces are
			Full Idea: For Wittgenstein, just as pieces in a game such as chess are defined by the rules that govern their moves, the meanings of words are similarly defined by the rules that govern their employment.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by Robert Fogelin - Walking the Tightrope of Reason Ch.2
			A reaction: Fogelin's note points out that it is more complex than this. It is hard to dispute the chess case, but while words like 'and' and 'not' may be given entirely functional definitions, others don't work like that: John, run, red, solid, pain, ow! ….

	p.91	6501	As sense-data are necessarily private, they are attacked by Wittgenstein's objections
			Full Idea: Sense-data are usually conceived as necessarily private to individual observers, so the final crisis for the empiricist conception of perception was Wittgenstein's famous polemic against such private objects.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by Howard Robinson - Perception IV.1
			A reaction: Personally I remain unconvinced by Wittgenstein's very elusive argument, but I think there are plenty of other reasons for doubting whether the idea of sense-data throws much light on our understanding of the processes of perception.

	p.209	7055	Externalist accounts of mental content begin in Wittgenstein
			Full Idea: The roots of externalist accounts of mental content lie in Wittgenstein.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952]) by John Heil - From an Ontological Point of View 18.2 n1
			A reaction: This points to the key idea being that content involves the whole language community, rather than that it involves the physical stuffs of the world, such as water. I suspect that Wittgenstein is right, but Putnam is wrong.

§019	p.8	4136	To imagine a language means to imagine a form of life
			Full Idea: To imagine a language means to imagine a form of life.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §019)
			A reaction: I take this to be about the transparency of language, but it supports meaning as truth conditions, rather than as use.

§043	p.20	4137	In the majority of cases the meaning of a word is its use in the language
			Full Idea: For a large class of cases - though not for all - the meaning of a word is its use in the language.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §043)
			A reaction: Defended by Paul Horwich, but I don't like this. If "swordfish" is a password, its meaning and its use are miles apart. Meaning connects to reality, but use doesn't.

§047	p.22	4138	Is white simple, or does it consist of the colours of the rainbow?
			Full Idea: Is white simple, or does it consist of the colours of the rainbow?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §047)
			A reaction: A nice challenge to externalism. White remains simple long after experts have told us it is complex.

§049	p.24	4139	Naming is a preparation for description
			Full Idea: Naming is a preparation for description.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §049)
			A reaction: Something has to be the starting point for a description. And yet a description could turn out to be an elaborate name.

§050	p.25	4140	The standard metre in Paris is neither one metre long nor not one metre long
			Full Idea: There is one thing of which one can say neither that it is one metre long, nor that it is not one metre long, and that is the standard metre in Paris.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §050)
			A reaction: The remark which inspired Kripke's causal theory. Clearly W. is wrong, because it is one metre long, but why is it that length?

§067	p.32	4141	Various games have a 'family resemblance', as their similarities overlap and criss-cross
			Full Idea: I shall say 'games' form a family, with a 'family resemblance', for the resemblances within a family - build, eyes, temperament etc. - overlap and criss-cross in the same way.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §067)
			A reaction: A very helpful idea for the nominalist view of universals, particularly for showing how concepts shade off indeterminately at the edges.

§079	p.31	4946	A name is not determined by a description, but by a cluster or family
			Full Idea: According to Wittgenstein (and Searle) the referent of a name is determined not by a single description but by some cluster or family.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952], §079) by Saul A. Kripke - Naming and Necessity lectures Lecture 1
			A reaction: It is because of this characteristically woolly, indeterminate and relativist view of Wittgenstein that I (and most people) find Kripke's notion of a 'baptism' so refreshing. It cuts throught the fog of language, and connects to reality.

§109	p.-24	2512	Philosophy is a battle against the bewitchment of our intelligence by means of language
			Full Idea: Philosophical problems are solved, not by giving new information, but by arranging what we have already known. Philosophy is a battle against the bewitchment of our intelligence by means of language.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §109), quoted by Jerrold J. Katz - Realistic Rationalism Int.xi
			A reaction: A philosophical dispute can be settled by a piece of information, which may be already known to you, but new to me. Philosophical discussion can also point to a scientific research programme - i.e. a need for new information. I like the first sentence.

§125	p.40	6566	The problem is to explain the role of contradiction in social life
			Full Idea: When a contradiction appears, we say: "I didn't mean it like that"; the civil status of a contradiction, or its status in civil life: there is the philosophical problem.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §125), quoted by Robert Fogelin - Walking the Tightrope of Reason Ch.2
			A reaction: The point is that logical concepts such as contradiction are conventional, and not all-or-nothing, so we might agree that you didn't really contradict yourself (when perhaps you uttered a witty ironic paradox). I don't see the problem as philosophical.

§198	p.81	4142	To understand a sentence means to understand a language
			Full Idea: To understand a sentence means to understand a language.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §198)
			A reaction: Does this make learning a language logically impossible? Helen Keller only knew one word at the beginning.

§201	p.81	6165	Every course of action can either accord or conflict with a rule, so there is no accord or conflict
			Full Idea: Paradox: no course of action could be determined by a rule, because every course of action can be made out to accord with the rule. Answer: if everything can accord with the rule, then everything can conflict with it, so there is no accord or conflict.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §201)
			A reaction: This is a very interesting claim which goes beyond the private language question. It seems to imply, for example, Dancy's 'Particularism' about morality, which is a general rejection of rules and principles in moral thought.

§202	p.81	4143	One cannot obey a rule 'privately', because that is a practice, not the same as thinking one is obeying
			Full Idea: 'Obeying a rule' is a practice. And to think one is obeying a rule is not to obey a rule. Hence it is not possible to obey a rule 'privately': otherwise thinking one was obeying a rule would be the same thing as obeying it.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §202)
			A reaction: The core of the Private Language argument. But if I drive on the right erroneously thinking it is the law, I can still make progress until I meet someone.

§202	p.93	6166	Was Wittgenstein's problem between individual and community, or between occasions for an individual?
			Full Idea: There are two interpretations of Wittgenstein here: the community interpretation sees error in a rule between the individual and the community, where the individual interpretation sees the problem between repeated occasions in the use of a sign.
			From: comment on Ludwig Wittgenstein (Philosophical Investigations [1952], §202) by Mark Rowlands - Externalism Ch.5
			A reaction: Rowlands brings out how a lot hangs on which of these two interpretations we opt for, but also that if the individual has a problem, this may logically imply the same problem for the community. The individual interpretation would be a deeper problem.

§202	p.95	6169	We do not achieve meaning and understanding in our heads, but in the world
			Full Idea: For Wittgenstein, meaning and understanding are not things that we do or achieve in our heads; they are things we achieve in the world.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952], §202) by Mark Rowlands - Externalism Ch.5
			A reaction: Can't we achieve anything in our heads? Mental arithmetic seems to be fairly mental, unless we are going to be absurdly behaviouristic. If we can achieve some things in our heads, why not lots of things?

§206	p.82	4144	Common human behaviour enables us to interpret an unknown language
			Full Idea: The common behaviour of mankind is the system of reference by means of which we interpret an unknown language.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §206)
			A reaction: This is a behaviourist spin on the idea of charity, but it leads to Davidson's assumption that most alien beliefs must be true.

§242	p.88	11049	To communicate, language needs agreement in judgment as well as definition
			Full Idea: If language is to be a means of communication there must be agreement not only in definitions but also (queer as this may sound) in judgments.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §242)
			A reaction: If someone is locked into a highly alien viewpoint, then communication with them does seem to be virtually impossible. Amenability to reason, and consensus on elementary facts, seems to be the sine qua non of communication.

§244	p.89	4145	How do words refer to sensations?
			Full Idea: How do words refer to sensations?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §244)
			A reaction: A very nice question, to be remembered when discussing how we refer to beauty, gold, water or the present King of France.

§246	p.89	5676	To say that I 'know' I am in pain means nothing more than that I AM in pain
			Full Idea: As the word is normally used, it can't be said of me at all that I 'know' I am in pain; what is it supposed to mean - except perhaps that I am in pain?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §246)
			A reaction: This raises the question of whether self-consciousness implies self-knowledge, and suggests that it doesn't. All our normal talk of knowledge requires some sort of reliable justification of beliefs, and we can't drop that in the case of self-knowledge.

§257	p.92	7875	If a brilliant child invented a name for a private sensation, it couldn't communicate it
			Full Idea: Let's assume the child is a genius and itself invents a name for the sensation! - But then, of course, he couldn't make himself understood when he used the word.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §257)
			A reaction: [His example is a sensation with no behaviour] Sensations are not just related to behaviour; they are related to external objects, and to parts of the body. We doubt the sensations of others if they can't name the object or the body part.

§265	p.94	4146	We cannot doublecheck mental images for correctness (or confirm news with many copies of the paper)
			Full Idea: If the mental image of a train timetable cannot itself be tested for correctness, how can it confirm the correctness of the first memory? (As if someone were to buy several copies of the morning paper to assure himself that what it said was true).
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §265)
			A reaction: An important point for the epistemological sceptic. Could God do an infinite regress of checks on the truth of his mental images?

§293	p.100	4147	If we only named pain by our own case, it would be like naming beetles by looking in a private box
			Full Idea: If someone says he only knows what pain is from his own case, suppose everyone had a box with something in it (a 'beetle'). We can't see into other boxes, so we say what a beetle is by looking in our own box. The contents of each box could be different.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §293)
			A reaction: But pain is private. Children must guess the meaning of parts of the language that refer to inner experience, like 'sad' or 'hopeful'. Body language brings our private concepts together, but error seems possible.

§293	p.100	5663	It is irresponsible to generalise from my own case of pain to other people's
			Full Idea: If I say of myself that it is only from my own case that I know what the word 'pain' means - must I not say the same of other people too? And how can I generalise from the one case so irresponsibly?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §293)
			A reaction: This is the best known objection to Mill's Argument from Analogy for other minds. It appears to be induction from a single instance. The better approach seems to be ABduction (best explanation), in which my own case is just some evidence.

§293	p.282	5659	If the reference is private, that is incompatible with the sense being public
			Full Idea: Wittgenstein's claim is that the assumption that the reference is private (being observable to one person alone) is incompatible with the hypothesis that the sense is public.
			From: report of Ludwig Wittgenstein (Philosophical Investigations [1952], §293) by Roger Scruton - Short History of Modern Philosophy Ch.19
			A reaction: An illuminating summary, showing the link between the private language argument and modern 'externalism' about the meaning of concepts (e.g. Idea 4099). I still don't find Wittgenstein's claim conclusive. Something is definitely private.

§302	p.101	19272	To imagine another's pain by my own, I must imagine a pain I don't feel, by one I do feel
			Full Idea: If one has to imagine someone else's pain on the model of one's own, this is none too easy a thing to do: for I have to imagine pain which I do not feel on the model of pain which I do not feel.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §302)
			A reaction: I just don't feel a deep problem here. Wittgenstein didn't know about mirror neurons, which trigger in me a reaction like the one causing your behaviour.

§309	p.103	4148	What is your aim in philosophy? - To show the fly the way out of the fly-bottle
			Full Idea: What is your aim in philosophy? - To show the fly the way out of the fly-bottle.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §309)
			A reaction: Ridiculous. Trying to think about thought is not a pointless buzzing - it is an attempt by humans to become like gods.

§329	p.107	4149	We don't have 'meanings' in our minds in addition to verbal expressions
			Full Idea: When I think in language, there aren't 'meanings' going through my mind in addition to the verbal expressions.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §329)
			A reaction: No, but words have properties, like being meaningful, or long, or beautiful. They are not abstractions, or empty counters which can be used for anything.

§353	p.112	4150	Asking about verification is only one way of asking about the meaning of a proposition
			Full Idea: Asking whether and how a proposition can be verified is only a particular way of asking 'How do you mean?' The answer is a contribution to the grammar of the proposition.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §353)
			A reaction: 'How' a proposition is verified seems utterly irrelevant. What situation in reality provides the verification must have something to do with the meaning. Cat-on-mat is what counts, not whether you see it, hear it or smell it.

§371-3	p.116	15106	Essence is expressed by grammar
			Full Idea: Essence is expressed by grammar. ...Grammar tells us what kind of object anything is.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §371-3)
			A reaction: Enigmatic, as usual. The second part seems to imply sortal essentialism, though the emphasis on grammar seems to make it highly conventional, rather than a reflection of 'real' sorts.

§373	p.116	4151	Grammar tells what kind of object anything is - and theology is a kind of grammar
			Full Idea: Grammar tells what kind of object anything is. (Theology as grammar)
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §373)
			A reaction: A classic twentieth century blunder, originating in Frege and culminating in Quine, of thinking that the analysis of language is the last word in ontology.

§380	p.117	4152	Getting from perceptions to words cannot be a private matter; the rules need an institution of use
			Full Idea: I could not apply any rules to a private transition from what is seen to words. Here the rules really would hang in the air; for the institution of their use is lacking.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §380)
			A reaction: That puts the argument nicely. In studying art or wine you learn what to say about your private experiences.

§401	p.121	4153	Are sense-data the material of which the universe is made?
			Full Idea: Are sense-data the material of which the universe is made?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §401)
			A reaction: Presumably the question is meant to be absurd, and to a realist it is. You can't serious think that a filing cabinet is made of sensations.

§412	p.124	4154	Why are we not aware of the huge gap between mind and brain in ordinary life?
			Full Idea: Why does the feeling of an unbridgeable gulf between consciousness and brain-process not come into the considerations of our ordinary life?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §412)
			A reaction: Nice question. Presumably Wittgenstein has a quasi-behaviouristic answer. People don't now ignore it? They retreat into crazy spiritualism.

§435	p.128	4155	We all seem able to see quite clearly how sentences represent things when we use them
			Full Idea: It it be asked, "How do sentences manage to represent?" the answer might be, "Don't you know? You certainly see it when you use them." For nothing is concealed.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §435)
			A reaction: A tool isn't its use, even though it becomes obvious how a tool works when it is used. It has a use because it has a certain nature or property.

§473	p.134	6600	The belief that fire burns is like the fear that it burns
			Full Idea: The belief that fire will burn me is of the same kind as the fear that it will burn me.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §473)
			A reaction: Most of our beliefs are forced on us, rather than chosen, and this nice remark gives an indication of the reason. It dovetails with Peirce's pragmatic approach to be belief (e.g. Idea 6598), which is well developed by Robert Fogelin.

§510	p.140	4156	Make the following experiment: say "It's cold here" and mean "It's warm here"
			Full Idea: Make the following experiment: say "It's cold here" and mean "It's warm here".
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §510)
			A reaction: A lovely experiment, whatever it proves. It is easier if the meaning is the truth, rather than the words. I try to weld a new word onto my experience.

§570	p.151	4157	Concepts direct our interests and investigations, and express those interests
			Full Idea: Concepts lead us to make investigations; are the expression of our interest, and direct our interest.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §570)
			A reaction: This presumably points to the evolutionary origin of our concept-creating capacity, though I am not sure that it defines what a concept actually is.

§580	p.125	7092	If individuals can't tell if they are following a rule, how does a community do it?
			Full Idea: The problem facing a putative private language-user - namely, that he cannot tell whether he is, or only thinks he is, following a rule - also faces the community as a whole; how does the community tell whether it is following a rule?
			From: comment on Ludwig Wittgenstein (Philosophical Investigations [1952], §580) by A.C. Grayling - Wittgenstein Ch.3
			A reaction: Nice question. If you really get into the sceptical frame of mind that Wittgenstein reached about rules, almost everything seems impossible. How can I move? How can I speak? How can one instant follow another? How can I understand a word?

§580	p.153	4158	An 'inner process' stands in need of outward criteria
			Full Idea: An 'inner process' stands in need of outward criteria.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §580)
			A reaction: Why do processes need 'criteria'? I have never understood why I can't have private criteria, or at least private modifications of public criteria.

§621	p.161	6658	What is left over if I subtract my arm going up from my raising my arm?
			Full Idea: What is left over if I subtract the fact that my arm goes up from the fact that I raise my arm?
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], §621)
			A reaction: Wittgenstein's implication seems to be that nothing is left over, but I would have thought that the will was the thing left over when you decide to raise your arm, but then discover that you are paralysed.

116	p.108	22490	Bring words back from metaphysics to everyday use
			Full Idea: What we do is to bring words back from their metaphysical to their everyday use.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], 116), quoted by Philippa Foot - Natural Goodness 7 n16
			A reaction: A germ of ordinary language philosophy. It is wrong to think that metaphysics must be studied in the usages of ordinary language, but I strongly believe that words like 'essence' or 'objectivity' should retain their normal meaning when philosophising.

213	p.84	11079	How do I decide when to accept or obey an intuition?
			Full Idea: If intuition is an inner voice - how do I know how I am to obey it? And how do I know that it doesn't mislead me? For if it can guide me right, it can also guide me wrong. ((Intuition an unnecessary shuffle))
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], 213)
			A reaction: Presumably the last point, in brackets, means that you still have to evaluate the intuition, with which I would agree. I take judgement to occur in the space of reasons, to which intuition is a major contributor. Only a fool would just accept intuition.

II.13	p.231	12606	Man learns the concept of the past by remembering
			Full Idea: Man learns the concept of the past by remembering.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], II.13)
			A reaction: [quoted by Peacocke] Is it the case that we learn all of our concepts by doing? Obviously not, since we can be taught them. Could you have no long-term memories (head trauma), and be taught the concept of the past by someone else?

II.iv	p.178	19273	I don't have the opinion that people have minds; I just treat them as such
			Full Idea: My attitude towards him is an attitude towards a soul. I am not of the 'opinion' that he has a soul.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], II.iv)
			A reaction: This seems to be precisely Dennett's 'intentional stance', where we conjure up minds in things like chess-playing computers, irrespective of whether we believe they are conscious.

II.iv	p.178	4159	The human body is the best picture of the human soul
			Full Idea: The human body is the best picture of the human soul.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], II.iv)
			A reaction: Nice. How did we imagine the soul before reading that remark? My soul requires fingernails and eyelids in order to fulfil its essential nature.

II.x	p.190	4160	One can mistrust one's own senses, but not one's own beliefs
			Full Idea: One can mistrust one's own senses, but not one's own beliefs.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], II.x)
			A reaction: This seems right, because we don't choose our beliefs. We don't even choose whether to believe a sensation - we just focus harder until belief does or doesn't occur.

II.xi	p.223	4161	If a lion could talk, we could not understand him
			Full Idea: If a lion could talk, we could not understand him.
			From: Ludwig Wittgenstein (Philosophical Investigations [1952], II.xi)
			A reaction: How does he know these things?! We could at least know whether they talked or merely grunted, by studying their correlated behaviour. Cf. dolphins. I think he is wrong. All talk is understandable to a degree, even God's.

II.xi	p.447	7392	If a lion could talk, it would be nothing like other lions
			Full Idea: I think that if a lion could talk, that lion would have a mind so different from the general run of lion minds, that although we could understand him just fine, we would learn little about ordinary lions from him.
			From: comment on Ludwig Wittgenstein (Philosophical Investigations [1952], II.xi) by Daniel C. Dennett - Consciousness Explained 14.2
			A reaction: This is rather more sensible than Wittgenstein's famous enigmatic utterance.