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All the ideas for 'Mahaprajnaparamitashastra', 'Axiomatic Theories of Truth (2013 ver)' and 'Our Knowledge of the External World'

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32 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
A sense of timelessness is essential to wisdom [Russell]
     Full Idea: Both in thought and in feeling, to realize the unimportance of time is the gate of wisdom.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 6)
     A reaction: A very rationalist and un-Heraclitean view of wisdom. This picture may give wisdom a bad name, if wise people are (at a minimum) at least expected to give good advice about real life.
1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Philosophical disputes are mostly hopeless, because philosophers don't understand each other [Russell]
     Full Idea: Explicit controversy is almost always fruitless in philosophy, owing to the fact that no two philosophers ever understand one another.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 1)
     A reaction: Contemporaries don't even seem to read one another very much, especially these days, when there are thousands of professional philosophers. (If you are a professional, have you read all the works written by your colleagues and friends?)
1. Philosophy / E. Nature of Metaphysics / 3. Metaphysical Systems
Philosophical systems are interesting, but we now need a more objective scientific philosophy [Russell]
     Full Idea: The great systems of the past serve a very useful purpose, and are abundantly worthy of study. But something different is required if philosophy is to become a science, and to aim at results independent of the tastes of the philosophers who advocate them.
     From: Bertrand Russell (Our Knowledge of the External World [1914], Pref)
     A reaction: An interesting product of this move in philosophy is (about sixty years later) the work of David Lewis, who set out to be precise and scientific, and ended up creating a very personal system. Why not a collaborative system?
Hegel's confusions over 'is' show how vast systems can be built on simple errors [Russell]
     Full Idea: Hegel's confusion of the 'is' of predication with the 'is' of identity ...is an example of how, for want of care at the start, vast and imposing systems of philosophy are built upon stupid and trivial confusions.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 2 n1)
     A reaction: [He explains the confusion in more detail in the note] Russell cites an English translation, and I am wondering how this occurs in the German. Plato has been accused of similar elementary blunders about properties. Russell treats Berkeley similarly.
Philosophers sometimes neglect truth and distort facts to attain a nice system [Russell]
     Full Idea: The desire for unadulterated truth is often obscured, in professional philosophers, by love of system: the one little fact which will not come inside the philosophical edifice has to be pushed and tortured until it seems to consent.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 8)
     A reaction: Bit of hypocrisy here. Russell was continually trying to find a system, grounded in physics and logic. Presumably his shifting views are indications of integrity, because he changes the system rather than the facts.
1. Philosophy / E. Nature of Metaphysics / 4. Metaphysics as Science
Physicists accept particles, points and instants, while pretending they don't do metaphysics [Russell]
     Full Idea: Physicists, ignorant and contemptuous of philosophy, have been content to assume their particles, points and instants in practice, while contending, with ironical politeness, that their concepts laid no claim to metaphysical validity.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 4)
     A reaction: Presumably physicists are allowed to wave their hands and utter the word 'instrumentalism', and then get on with the job. They just have to ensure they never speculate about what is being measured.
1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
When problems are analysed properly, they are either logical, or not philosophical at all [Russell]
     Full Idea: Every philosophical problem, when it is subjected to the necessary analysis and purification, is found either to be not really philosophical at all, or else to be, in the sense in which we are using the word, logical.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 2)
     A reaction: [All Lecture 2 discusses 'logical'] I think Bertie was getting carried away here. In his life's corpus he barely acknowledges the existence of ethics, or political philosophy, or aesthetics. He never even engages with 'objects' the way Aristotle does.
3. Truth / A. Truth Problems / 2. Defining Truth
If we define truth, we can eliminate it [Halbach/Leigh]
     Full Idea: If truth can be explicitly defined, it can be eliminated.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.3)
     A reaction: That we could just say p corresponds to the facts, or p coheres with our accepted beliefs, or p is the aim of our enquiries, and never mention the word 'true'. Definition is a strategy for reduction or elimination.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / b. Satisfaction and truth
If a language cannot name all objects, then satisfaction must be used, instead of unary truth [Halbach/Leigh]
     Full Idea: If axioms are formulated for a language (such as set theory) that lacks names for all objects, then they require the use of a satisfaction relation rather than a unary truth predicate.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 3.3)
     A reaction: I take it this is an important idea for understanding why Tarski developed his account of truth based on satisfaction.
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
Semantic theories need a powerful metalanguage, typically including set theory [Halbach/Leigh]
     Full Idea: Semantic approaches to truth usually necessitate the use of a metalanguage that is more powerful than the object-language for which it provides a semantics. It is usually taken to include set theory.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1)
     A reaction: This is a motivation for developing an axiomatic account of truth, that moves it into the object language.
3. Truth / F. Semantic Truth / 2. Semantic Truth
The T-sentences are deductively weak, and also not deductively conservative [Halbach/Leigh]
     Full Idea: Although the theory is materially adequate, Tarski thought that the T-sentences are deductively too weak. …Also it seems that the T-sentences are not conservative, because they prove in PA that 0=0 and ¬0=0 are different, so at least two objects exist.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 3.2)
     A reaction: They are weak because they can't prove completeness. This idea give two reasons for looking for a better theory of truth.
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
A natural theory of truth plays the role of reflection principles, establishing arithmetic's soundness [Halbach/Leigh]
     Full Idea: If a natural theory of truth is added to Peano Arithmetic, it is not necessary to add explicity global reflection principles to assert soundness, as the truth theory proves them. Truth theories thus prove soundess, and allows its expression.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.2)
     A reaction: This seems like a big attraction of axiomatic theories of truth for students of metamathematics.
If deflationary truth is not explanatory, truth axioms should be 'conservative', proving nothing new [Halbach/Leigh]
     Full Idea: If truth does not have any explanatory force, as some deflationists claim, the axioms of truth should not allow us to prove any new theorems that do not involve the truth predicate. That is, a deflationary axiomatisation of truth should be 'conservative'.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.3)
     A reaction: So does truth have 'explanatory force'? These guys are interested in explaining theorems of arithmetic, but I'm more interested in real life. People do daft things because they have daft beliefs. Logic should be neutral, but truth has values?
3. Truth / G. Axiomatic Truth / 2. FS Truth Axioms
The FS axioms use classical logical, but are not fully consistent [Halbach/Leigh]
     Full Idea: It is a virtue of the Friedman-Sheard axiomatisation that it is thoroughly classical in its logic. Its drawback is that it is ω-inconsistent. That is, it proves &exists;x¬φ(x), but proves also φ(0), φ(1), φ(2), …
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 4.3)
     A reaction: It seems the theory is complete (and presumably sound), yet not fully consistent. FS also proves the finite levels of Tarski's hierarchy, but not the transfinite levels.
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
KF is formulated in classical logic, but describes non-classical truth, which allows truth-value gluts [Halbach/Leigh]
     Full Idea: KF is formulated in classical logic, but describes a non-classical notion of truth. It allow truth-value gluts, making some sentences (such as the Liar) both true and not-true. Some authors add an axiom ruling out such gluts.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 4.4)
     A reaction: [summary, which I hope is correct! Stanford is not wholly clear]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Logic gives the method of research in philosophy [Russell]
     Full Idea: Logic gives the method of research in philosophy, just as mathematics gives the method in physics.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 8)
     A reaction: I'm struck by how rarely philosophers actually prove anything. Mostly they just use the language of logic as a tool for disambiguation. Only a tiny handful of philosophers can actually create sustained and novel proofs.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
The logical connectives are not objects, but are formal, and need a context [Russell]
     Full Idea: Such words as 'or' and 'not' are not names of definite objects, but are words that require a context in order to have a meaning. All of them are formal.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 7)
     A reaction: [He cites Wittgenstein's 1922 Tractatus in a footnote - presumably in a later edition than 1914] This is the most famous idea which Russell acquired from Wittgenstein. It was yet another step in his scaling down of ontology.
5. Theory of Logic / L. Paradox / 4. Paradoxes in Logic / a. Achilles paradox
The tortoise won't win, because infinite instants don't compose an infinitely long time [Russell]
     Full Idea: The idea that an infinite number of instants make up an infinitely long time is not true, and therefore the conclusion that Achilles will never overtake the tortoise does not follow.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 6)
     A reaction: Aristotle spotted this, but didn't express it as clearly as Russell.
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
Atomic facts may be inferrable from others, but never from non-atomic facts [Russell]
     Full Idea: Perhaps one atomic fact may sometimes be capable of being inferred from another, though I do not believe this to be the case; but in any case it cannot be inferred from premises no one of which is an atomic fact.
     From: Bertrand Russell (Our Knowledge of the External World [1914], p.48)
     A reaction: I prefer Russell's caution to Wittgenstein's dogmatism. I presume utterly simple facts give you nothing to work with. Hegel thought that you could infer new concepts from given concepts.
7. Existence / D. Theories of Reality / 8. Facts / d. Negative facts
A positive and negative fact have the same constituents; their difference is primitive [Russell]
     Full Idea: It must not be supposed that a negative fact contains a constituent corresponding to the word 'not'. It contains no more constituents than a positive fact of the correlative positive form. The differenece between the two forms is ultimate and irreducible.
     From: Bertrand Russell (Our Knowledge of the External World [1914], VIII.279), quoted by Michael Potter - The Rise of Analytic Philosophy 1879-1930 41 'Neg'
     A reaction: ['Harvard Lectures'] The audience disliked this. How does one fact exclude the other fact? Potter asks whether absence is a fact, and whether an absence can be a truthmaker.
8. Modes of Existence / A. Relations / 1. Nature of Relations
With asymmetrical relations (before/after) the reduction to properties is impossible [Russell]
     Full Idea: When we come to asymmetrical relations, such as before and after, greater and less etc., the attempt to reduce them to properties becomes obviously impossible.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 2)
     A reaction: The traditional Aristotelian reduction to properties is attributed by Russell to logic based on subject-predicate. As an example he cites being greater than as depending on more than the mere magnitudes of the entities. Direction of the relation.
8. Modes of Existence / B. Properties / 11. Properties as Sets
When we attribute a common quality to a group, we can forget the quality and just talk of the group [Russell]
     Full Idea: When a group of objects have the similarity we are inclined to attribute to possession of a common quality, the membership of the group will serve all the purposes of the supposed common quality ...which need not be assumed to exist.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 2)
     A reaction: This is the earliest account I have found of properties being treated as sets of objects. It more or less coincides with the invention of set theory. I am reminded of Idea 9208. What is the bazzing property? It's what those three things have in common.
8. Modes of Existence / B. Properties / 12. Denial of Properties
We can reduce properties to true formulas [Halbach/Leigh]
     Full Idea: One might say that 'x is a poor philosopher' is true of Tom instead of saying that Tom has the property of being a poor philosopher. We quantify over formulas instead of over definable properties, and thus reduce properties to truth.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.1)
     A reaction: [compressed] This stuff is difficult (because the axioms are complex and hard to compare), but I am excited (yes!) about this idea. Their point is that you need a truth predicate within the object language for this, which disquotational truth forbids.
8. Modes of Existence / E. Nominalism / 1. Nominalism / c. Nominalism about abstracta
Nominalists can reduce theories of properties or sets to harmless axiomatic truth theories [Halbach/Leigh]
     Full Idea: The reduction of second-order theories (of properties or sets) to axiomatic theories of truth is a form of reductive nominalism, replacing existence assumptions (e.g. comprehension axioms) by innocuous assumptions about the truth predicate.
     From: Halbach,V/Leigh,G.E. (Axiomatic Theories of Truth (2013 ver) [2013], 1.1)
     A reaction: I'm currently thinking that axiomatic theories of truth are the most exciting development in contemporary philosophy. See Halbach and Horsten.
11. Knowledge Aims / C. Knowing Reality / 1. Perceptual Realism / c. Representative realism
Science condemns sense-data and accepts matter, but a logical construction must link them [Russell]
     Full Idea: Men of science condemn immediate data as 'merely subjective', while maintaining the truths of physics from those data. ...The only justification possible for this must be one which exhibits matter as a logical construction from sense-data.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 4)
     A reaction: Since we blatantly aren't doing logic when we stare out of the window, this aspires to finding something like the 'logical form' of perception.
12. Knowledge Sources / B. Perception / 4. Sense Data / c. Unperceived sense-data
When sense-data change, there must be indistinguishable sense-data in the process [Russell]
     Full Idea: In all cases of sense-data capable of gradual change, we may find one sense-datum indistinguishable from another, and that indistinguishable from a third, while yet the first and third are quite easily distinguishable.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 5)
     A reaction: This point is key to the sense-data theory, because it gives them independent existence, standing between reality and subjective experience. It is also the reason why they look increasingly implausible, if they may not be experienced.
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Empirical truths are particular, so general truths need an a priori input of generality [Russell]
     Full Idea: All empirical evidence is of particular truths. Hence, if there is any knowledge of general truths at all, there must be some knowledge of general truths which is independent of empirical evidence.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 2)
     A reaction: Humean empiricists respond by being a sceptical of general truths. At this stage of his career Russell looks like a thoroughgoing rationalist, and he believes in the reality of universals, relations and propositions. He became more empirical later.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / b. Pro-coherentism
Objects are treated as real when they connect with other experiences in a normal way [Russell]
     Full Idea: Objects of sense are called 'real' when they have the kind of connection with other objects of sense which experience has led us to regard as normal; when they fail this, they are called 'illusions'.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 3)
     A reaction: This rests rather too much on the concept of 'normal', but offers an attractive coherence account of perception. Direct perceptions are often invoked by anti-coherentists, but I think coherence is just as much needed in that realm.
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
Global scepticism is irrefutable, but can't replace our other beliefs, and just makes us hesitate [Russell]
     Full Idea: Universal scepticism, though logically irrefutable, is practically barren; it can only, therefore, give a certain flavour of hesitancy to our beliefs, and cannot be used to substitute other beliefs for them.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 3)
     A reaction: Spot on. There is no positive evidence for scepticism, so must just register it as the faintest of possibilities, like the existence of secretive fairies.
15. Nature of Minds / A. Nature of Mind / 4. Other Minds / c. Knowing other minds
Other minds seem to exist, because their testimony supports realism about the world [Russell, by Grayling]
     Full Idea: Russell gives an argument that other minds exist, because if one is entitled to believe this, then one can rely on the testimony of others, which, jointly with one's own experience, will give powerful support to the view that there a real spatial world.
     From: report of Bertrand Russell (Our Knowledge of the External World [1914], 3) by A.C. Grayling - Russell Ch.2
     A reaction: I rather like this argument. It is quite close to Wittgenstein's Private Language Argument, which also seems to refute scepticism about other minds. I think Russell's line, using testimony, knowledge and realism, may be better than Wittgenstein's.
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna]
     Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom.
     From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88)
     A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate').
27. Natural Reality / D. Time / 2. Passage of Time / a. Experience of time
We never experience times, but only succession of events [Russell]
     Full Idea: There is no reason in experience to suppose that there are times as opposed to events: the events, ordered by the relations of simultaneity and succession, are all that experience provides.
     From: Bertrand Russell (Our Knowledge of the External World [1914], 4)
     A reaction: We experience events, but also have quite an accurate sense of how much time has passed during the occurrence of events. If asked how much time has lapsed, why don't we say '32 events'? How do we distinguish long events from short ones?