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All the ideas for 'A Discourse on Method', 'Approaches to Intentionality' and 'Logical Properties'

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68 ideas

1. Philosophy / D. Nature of Philosophy / 1. Philosophy
Slow and accurate thought makes the greatest progress [Descartes]
     Full Idea: Those who go forward only very slowly can progress much further if they always keep to the right path, than those who run and wander off it.
     From: René Descartes (A Discourse on Method [1637], §1.2)
     A reaction: Like Descartes' 'Method'. This seems to place a low value on 'nous' or intuition.
1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
Most things in human life seem vain and useless [Descartes]
     Full Idea: Looking at the various activities and enterprises of mankind with the eye of a philosopher, there is hardly one which does not seem to me vain and useless.
     From: René Descartes (A Discourse on Method [1637], §1.3)
     A reaction: Well, yes. The obvious retort is that everything is vain and useless; or if not, then certainly metaphysics is. Useful for what? Is ornamental gardening useless, or sport? Art? What is the use of cosmology? He's right, of course.
Almost every daft idea has been expressed by some philosopher [Descartes]
     Full Idea: There is nothing one can imagine so strange or so unbelievable that has not been said by one or other of the philosophers.
     From: René Descartes (A Discourse on Method [1637], §2.16)
     A reaction: Actually I think that extensive areas of logical possibilities for existence remain totally unexplored. On the other hand, most of the metaphysical beliefs of most of the human race, including the majority of philosophers, strike me as being false.
2. Reason / A. Nature of Reason / 4. Aims of Reason
Methodical thinking is cautious, analytical, systematic, and panoramic [Descartes, by PG]
     Full Idea: Descartes' four principles for his method of thinking are: be cautious, analyse the problem, be systematic from simple to complex, and keep an overview of the problem
     From: report of René Descartes (A Discourse on Method [1637], §2.18) by PG - Db (ideas)
2. Reason / D. Definition / 1. Definitions
Definitions identify two concepts, so they presuppose identity [McGinn]
     Full Idea: Any definition must presuppose the notion of identity precisely because a definition affirms the identity of two concepts.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: McGinn is arguing that identity is fundamental to thought, and this seems persuasive. It may be, though, that while identities are inescapable, definitions are impossible.
2. Reason / F. Fallacies / 2. Infinite Regress
Regresses are only vicious in the context of an explanation [McGinn]
     Full Idea: Regresses are only vicious in the context of some explanatory aim, not in themselves.
     From: Colin McGinn (Logical Properties [2000], Ch.2 n11)
     A reaction: A nice point. It is not quite clear how 'pure' reason could ever be vicious, or charming, or sycophantic. The problem about a vicious regress is precisely that it fails to explain anything. Now benign regresses are something else… (see Idea 2523)
2. Reason / F. Fallacies / 4. Circularity
Clear and distinct conceptions are true because a perfect God exists [Descartes]
     Full Idea: That the things we grasp very clearly and very distinctly are all true, is assured only because God is or exists, and because he is a perfect Being.
     From: René Descartes (A Discourse on Method [1637], §4.38)
3. Truth / A. Truth Problems / 4. Uses of Truth
Truth is a method of deducing facts from propositions [McGinn]
     Full Idea: Truth is essentially a method of deducing facts from propositions.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: Very persuasive. McGinn is offering a disquotational account of truth, but in a robust form. Of course, deduction normally takes the form of moving infallibly from one truth to another, but that model of deduction won't fit this particular proposal.
3. Truth / A. Truth Problems / 8. Subjective Truth
Truth is clear and distinct conception - of which it is hard to be sure [Descartes]
     Full Idea: I take it as a general rule that the things we conceive very clearly and very distinctly are all true, but that there is merely some difficulty in properly discerning which are those which we distinctly conceive.
     From: René Descartes (A Discourse on Method [1637], §4.33)
3. Truth / C. Correspondence Truth / 3. Correspondence Truth critique
'Snow does not fall' corresponds to snow does fall [McGinn]
     Full Idea: We can say that the proposition that snow does not fall from the sky corresponds to the fact that snow does fall from the sky - in the sense that there is a mapping from fact to proposition.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: A very nice difficulty for the correspondence theory. It becomes essential to say how the two things correspond before it can offer any sort of account of the truth-relation.
The idea of truth is built into the idea of correspondence [McGinn]
     Full Idea: The correspondence theory has an air of triviality, and hence undeniability, but this is because it implicitly builds the idea of truth into the notion of correspondence.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: If this is accepted, it is a really fatal objection to the theory. Russell tried to use the idea of 'congruency' between beliefs and reality, but that may be open to the same objection. McGinn is claiming that truth is essentially indefinable.
3. Truth / D. Coherence Truth / 2. Coherence Truth Critique
The coherence theory of truth implies idealism, because facts are just coherent beliefs [McGinn]
     Full Idea: If 'snow falls from the sky' is true iff it coheres with other beliefs, this is a form of idealism; snow could surely fall from sky even if there were no beliefs in the world to cohere with each other.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: The coherence theory of truth strikes me as yet another blunder involving a confusion of ontology and epistemology. Of course, idealism may be true, but I have yet to hear a good reason why I should abandon commonsense realism.
3. Truth / H. Deflationary Truth / 3. Minimalist Truth
Truth is the property of propositions that makes it possible to deduce facts [McGinn]
     Full Idea: Truth is a property of a proposition from which one can deduce the fact stated by the proposition.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: This is McGinn's explanation of the disquotational account of truth ('p' is true iff p). The redundancy theorist would reply that you can deduce p from 'p' without mentioning truth, but it remains to ask why this deduction is possible.
Without the disquotation device for truth, you could never form beliefs from others' testimony [McGinn]
     Full Idea: Imagine being in a community which had no concept of truth; ..you cannot disquote on p and hence form beliefs about the world as a result of testimony, since you lack the device of disquotation that is the essence of truth.
     From: Colin McGinn (Logical Properties [2000], Ch.5)
     A reaction: Whether his theory is right or not, the observation that testimony is the really crucial area where we must have a notion of truth is very good. How about 'truth is what turns propositions into beliefs'?
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
In 'x is F and x is G' we must assume the identity of x in the two statements [McGinn]
     Full Idea: If we say 'for some x, x is F and x is G' we are making tacit appeal to the idea of identity in using 'x' twice here: it has to be the same object that is both F and G.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: This may well be broadened to any utterances whatsoever. The only remaining question is to speculate about whether it is possible to think without identities. The Hopi presumably gave identity to processes rather objects. How does God think?
Both non-contradiction and excluded middle need identity in their formulation [McGinn]
     Full Idea: To formulate the law of non-contradiction ('nothing can be both F and non-F') and the law of excluded middle ('everything is either F or it is not-F'), we need the concept of identity (in 'nothing' and 'everything').
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: Two good examples in McGinn's argument that identity is basic to all thinking. But the argument also works to say that necessity is basic (since both laws claim it) and properties are basic. Let's just declare everything 'basic', and we can all go home.
Identity is unitary, indefinable, fundamental and a genuine relation [McGinn]
     Full Idea: I have endorsed four main theses about identity: it is unitary, it is indefinable, it is fundamental, and it is a genuine relation
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: That it is fundamental to our thinking seems certain (but to all possible thought?). That it is a relation looks worth questioning. One might challenge unitary by comparing the identity of numbers, values, electrons and continents. I can't define it.
5. Theory of Logic / G. Quantification / 1. Quantification
The quantifier is overrated as an analytical tool [McGinn]
     Full Idea: The quantifier has been overrated as a tool of logical and linguistic analysis.
     From: Colin McGinn (Logical Properties [2000], Pref)
     A reaction: I find this proposal quite thrilling. Twentieth century analytical philosophy has been in thrall to logic, giving the upper hand in philosophical discussion to the logicians, who are often not very good at philosophy.
Existential quantifiers just express the quantity of things, leaving existence to the predicate 'exists' [McGinn]
     Full Idea: What the existential quantifier does is indicate the quantity of things in question - it says that some are; it is left up to the predicate 'exists' to express existence.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This seems right. The whole quantification business seems like a conjuring trick to conceal the embarrassingly indefinable and 'metaphysical' notion of 'existence'. Cf Idea 7697.
5. Theory of Logic / G. Quantification / 3. Objectual Quantification
'Partial quantifier' would be a better name than 'existential quantifier', as no existence would be implied [McGinn]
     Full Idea: We would do much better to call 'some' the 'partial quantifier' (rather than the 'existential quantifier'), on analogy with the universal quantifier - as neither of them logically implies existence.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: Like McGinn's other suggestions in this chapter, this strikes me as a potentially huge clarification in linguistic analysis. I wait with interest to see whether the philosophical logicians take it up. I bet they don't.
5. Theory of Logic / G. Quantification / 7. Unorthodox Quantification
We need an Intentional Quantifier ("some of the things we talk about.."), so existence goes into the proposition [McGinn]
     Full Idea: We could introduce an 'intentional quantifier' (Ix) which means 'some of the things we talk about..'; we could then say 'some of the things we talk about are F and exist' (Ix, x is F and x exists).
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This immediately strikes me as a promising contribution to the analytical toolkit. McGinn is supporting his view that existence is a predicate, and so belongs inside the proposition, not outside.
7. Existence / A. Nature of Existence / 1. Nature of Existence
Existence is a primary quality, non-existence a secondary quality [McGinn]
     Full Idea: Existence is like a primary quality; non-existence is like a secondary quality.
     From: Colin McGinn (Logical Properties [2000], Ch.2 n29)
     A reaction: Since McGinn thinks existence really is a property, and hence, presumably, a predicate, I don't quite see why he uses the word "like". A nicely pithy and thought-provoking remark.
7. Existence / A. Nature of Existence / 6. Criterion for Existence
Existence can't be analysed as instantiating a property, as instantiation requires existence [McGinn]
     Full Idea: Paraphrasing existence statements into statements about the instantiation of a property does not establish that existence is not a predicate, since the notion of instantiation must be taken to have existence built into it.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: Thank you, Colin McGinn! This now strikes me as so obvious that it is astonishing that for the whole of the twentieth century no one seems to have said it. For a century philosophers had swept the ontological dirt under the mat.
We can't analyse the sentence 'something exists' in terms of instantiated properties [McGinn]
     Full Idea: The problems of the orthodox view are made vivid by analysis of the sentence 'something exists'; this is meaningful and true, but what property are we saying is instantiated here?
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: A very nice point. McGinn claims that existence is a property, a very generalised one. Personally I don't think anyone is even remotely clear what a property is, so the whole discussion is a bit premature. Must properties have causal powers?
7. Existence / D. Theories of Reality / 3. Reality
If causal power is the test for reality, that will exclude necessities and possibilities [McGinn]
     Full Idea: Whether my body weight is necessary or contingent makes no difference at all to my causal powers, so modality is epiphenomenal; if you took causal potential as a test of reality you would have to declare modes unreal.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: We could try analysing modality into causal terms, as Lewis proposes with quantification across worlds, or as Quine proposes by reduction to natural regularities. I am not sure what it would mean to declare that modes are 'real'.
7. Existence / D. Theories of Reality / 8. Facts / b. Types of fact
Facts are object-plus-extension, or property-plus-set-of-properties, or object-plus-property [McGinn]
     Full Idea: A fact may be an object and an extension (Quine's view), or a property and a set of properties, or an object and a property; the view I favour is the third one, which seems the most natural.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: Personally I tend to use the word 'fact' in a realist and non-linguistic way. There must be innumerable inexpressible facts, such as the single pattern made by all the particles of the universe. McGinn seems to be talking of 'atomic facts'. See Idea 6111.
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity propositions are not always tautological, and have a key epistemic role [McGinn]
     Full Idea: Identity propositions are not always analytic or a priori (as Frege long ago taught us) so there is nothing trivial about such propositions; the claim of redundancy ignores the epistemic role that the concept of identity plays.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: He is referring to Frege's Morning Star/Evening Star distinction (Idea 4972). Wittgenstein wanted to eliminate our basic metaphysics by relabelling it as analytic or tautological, but his project failed. Long live metaphysics!
9. Objects / F. Identity among Objects / 2. Defining Identity
Identity is as basic as any concept could ever be [McGinn]
     Full Idea: Identity has a universality and basicness that is hard to overstate; concepts don't get more basic than this - or more indispensable.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: I agree with this. It seems to me to follow that the natural numbers are just as basic, because they are entailed by the separateness of the identities of things. And the whole of mathematics is the science of the patterns within these numbers.
9. Objects / F. Identity among Objects / 4. Type Identity
Type-identity is close similarity in qualities [McGinn]
     Full Idea: Two things are said to be type-identical when they are similar enough to be declared qualitatively identical.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: A simple point which brings out the fact that type-identity is unlikely to be any sort of true identity (unless there is absolutely no different at all between two electrons, say).
Qualitative identity is really numerical identity of properties [McGinn]
     Full Idea: A statement of so-called qualitative identity is really a statement of numerical identity (that is, identity tout court) about the properties of the objects in question - assuming that there are genuine universals.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: We might agree that two cars are type-identical, even though (under the microscope) we decided that none of their properties were absolutely identical.
Qualitative identity can be analysed into numerical identity of the type involved [McGinn]
     Full Idea: We can analyse qualitative identity in terms of numerical identity, by saying that x and y are type-identical if there is a single type T that x and y both are, i.e. they both exemplify the same type.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: This just seems to shift the problem onto the words 'are' and 'exemplify'. This takes us back to the problem of things 'partaking' of Plato's Forms. Better to say that qualitative identity isn't identity - it is resemblance (see Idea 6045).
It is best to drop types of identity, and speak of 'identity' or 'resemblance' [McGinn]
     Full Idea: It would be better to drop talk of 'numerical' and 'qualitative' identity altogether, speaking instead simply of identity and resemblance.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n4)
     A reaction: This is the kind of beautifully simple proposal I pay analytical philosophers to come up with. I will attempt in future to talk either of 'identity' (which is strict), or 'resemblance' (which comes in degrees).
9. Objects / F. Identity among Objects / 5. Self-Identity
Existence is a property of all objects, but less universal than self-identity, which covers even conceivable objects [McGinn]
     Full Idea: Existence is a property universal to all objects that exist, somewhat like self-identity, but less universal, because self-identity holds of all conceivable objects, not merely those that happen to exist.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: This is a splendidly defiant response to the Kantian slogan that 'existence is not a predicate', and I find McGinn persuasive. I can still not find anyone to explain to me exactly what a property is, so I will reserve judgement.
Sherlock Holmes does not exist, but he is self-identical [McGinn]
     Full Idea: Sherlock Holmes does not exist, but he is self-identical (he is certainly not indentical to Dr Watson).
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: Most significant. Identity does not entail existence; identity is necessary for existence (I think) but not sufficient. But the notion of existence might be prior to the notion of identity, and the creation of Holmes be parasitic on real existence.
9. Objects / F. Identity among Objects / 6. Identity between Objects
All identity is necessary, though identity statements can be contingently true [McGinn]
     Full Idea: All identity is necessary, although there can be contingently true identity statements - those that contain non-rigid designators.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n5)
     A reaction: A nice case of the need to keep epistemology and ontology separate. An example might be 'The Prime Minister wears a wig', where 'Prime Minister' may not be a rigid designator. 'Winston wears a wig' will be necessary, if true (which it wasn't).
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Leibniz's Law says 'x = y iff for all P, Px iff Py' [McGinn]
     Full Idea: Leibniz's Law says 'x = y iff for all P, Px iff Py'.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: That is, two things are the same if when we say that one thing (x) has a property (P), then we are saying that the other thing (y) also has the property. A usefully concise statement of the Law.
Leibniz's Law is so fundamental that it almost defines the concept of identity [McGinn]
     Full Idea: Leibniz's Law, which a defender of relative identity might opt to reject, is so fundamental to the notion of identity that rejecting it amounts to changing the subject.
     From: Colin McGinn (Logical Properties [2000], Ch.1 n8)
     A reaction: The Law here is the 'indiscernibility of identicals'. I agree with McGinn, and anyone who loses their grip on this notion of identity strikes me as losing all grip on reality, and threatening their own sanity (well, call it their 'philosophical sanity').
Leibniz's Law presupposes the notion of property identity [McGinn]
     Full Idea: Leibniz's Law presupposes the notion of property identity.
     From: Colin McGinn (Logical Properties [2000], Ch.1)
     A reaction: A very important observation, because it leads to recognition of the way in which basic concepts and categories of thought interconnect. Which is more metaphysically basic, identity or properties? It is not easy to say…
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Modality is not objects or properties, but the type of binding of objects to properties [McGinn]
     Full Idea: Modality has a special ontological category: it consists neither in objects (possible worlds theory) nor in properties (predicate modifier view), but items I have called 'modes', ..which can be hard/soft/rigid/pliable binding of objects to properties.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: As so often, McGinn is very persuasive. Essentially he is proposing that modality is adverbial. He associates the middle view with David Wiggins.
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
If 'possible' is explained as quantification across worlds, there must be possible worlds [McGinn]
     Full Idea: If we replace modal words like 'possible' with quantification across worlds, clearly the notion of 'world' must exclude impossible worlds, otherwise 'possibly p' will be true if 'p' holds in an impossible world.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: The point here, of course, is that the question is being begged of what 'possible' and 'impossible' actually mean.
11. Knowledge Aims / A. Knowledge / 4. Belief / a. Beliefs
We can believe a thing without knowing we believe it [Descartes]
     Full Idea: The action of thought by which one believes a thing, being different from that by which one knows that one believes it, they often exist the one without the other.
     From: René Descartes (A Discourse on Method [1637], §3.23)
Belief is the most important propositional attitude [Lyons]
     Full Idea: Belief might be accorded the status of core or chief propositional attitude.
     From: William Lyons (Approaches to Intentionality [1995], p.126)
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
In morals Descartes accepts the conventional, but rejects it in epistemology [Roochnik on Descartes]
     Full Idea: Descartes' procedure for treating values (accepting normal conventions when faced with uncertainty) is the exact antithesis of that used to attain knowledge.
     From: comment on René Descartes (A Discourse on Method [1637], §3.23) by David Roochnik - The Tragedy of Reason p.73
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
In thinking everything else false, my own existence remains totally certain [Descartes]
     Full Idea: While I decided to think that everything was false, it followed necessarily that I who thought thus must be something; the truth 'I think therefore I am' was so certain that the most extravagant scepticism could never shake it.
     From: René Descartes (A Discourse on Method [1637], §4.32)
12. Knowledge Sources / A. A Priori Knowledge / 6. A Priori from Reason
I aim to find the principles and causes of everything, using the seeds within my mind [Descartes]
     Full Idea: I have tried to find in general the principles or first causes of everything which is or which may be in the world, ..without taking them from any other source than from certain seeds of truth which are naturally in our minds.
     From: René Descartes (A Discourse on Method [1637], §6.64)
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Understanding, rather than imagination or senses, gives knowledge [Descartes]
     Full Idea: Neither our imagination nor our senses could ever assure us of anything, if our understanding did not intervene.
     From: René Descartes (A Discourse on Method [1637], §4.37)
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Necessity and possibility are big threats to the empiricist view of knowledge [McGinn]
     Full Idea: It is clear that modality is a prima-facie threat to the usual kind of naturalistic-causal-empiricist theory of knowledge.
     From: Colin McGinn (Logical Properties [2000], Ch.4)
     A reaction: This is why modern empiricists spend of a lot of energy on trying to analyse counterfactuals and laws of nature. Rationalists are much happier to assert necessities a priori, but then they often don't have much basis for their claims.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / a. Foundationalism
I was searching for reliable rock under the shifting sand [Descartes]
     Full Idea: My whole plan had for its aim simply to give me assurance, and the rejection of shifting ground and sand in order to find rock or clay.
     From: René Descartes (A Discourse on Method [1637], §3.29)
     A reaction: I take this to be characteristic of an age when religion is being quietly rocked by the revival of ancient scepticism. If he'd settled for fallibilism, our civilization would have gone differently.
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Scepticism about reality is possible because existence isn't part of appearances [McGinn]
     Full Idea: Scepticism about the external world is possible because you can never build existence into the appearances, so it must always be inferred or assumed.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: When McGinn's claim that existence is a very universal property begins to produce interesting observations like this, I think we should take it very seriously.
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
When rebuilding a house, one needs alternative lodgings [Descartes]
     Full Idea: Before beginning to rebuild the house in which one lives…. one must also provide oneself with some other accommodation in which to be lodge conveniently while the work is going on.
     From: René Descartes (A Discourse on Method [1637], §3.22)
14. Science / A. Basis of Science / 3. Experiment
Only experiments can settle disagreements between rival explanations [Descartes]
     Full Idea: I observe almost no individual effect without immediately knowing that it can be deduced in many different ways, ..and I know of no way to resolve this but by experiments such that the results are different according to different explanations.
     From: René Descartes (A Discourse on Method [1637], §6.65)
15. Nature of Minds / A. Nature of Mind / 7. Animal Minds
Little reason is needed to speak, so animals have no reason at all [Descartes]
     Full Idea: Animals not only have less reason than men, but they have none at all; for we see that very little of it is required in order to be able to speak.
     From: René Descartes (A Discourse on Method [1637], §5.58)
15. Nature of Minds / B. Features of Minds / 4. Intentionality / b. Intentionality theories
Consciousness no longer seems essential to intentionality [Lyons]
     Full Idea: In contrast with Brentano and Husserl, consciousness or attention are no longer seen as essential to intentionality.
     From: William Lyons (Approaches to Intentionality [1995], Intro)
     A reaction: This strikes me as being correct, although there seem to be plenty of current philosophers who do not accept it (e.g. Searle). I think philosophy of mind may be stuck in the dark ages if thinkers don't accept this proposal.
16. Persons / B. Nature of the Self / 3. Self as Non-physical
I am a thinking substance, which doesn't need a place or material support [Descartes]
     Full Idea: I concluded that I was a substance, of which the whole essence or nature consists in thinking, and which, in order to exist, needs no place and depends on no material thing.
     From: René Descartes (A Discourse on Method [1637], §4.33)
     A reaction: To me that sounds like "I concluded that I wasn't a human being", which highlights the bizarre wishful thinking that seems to have gripped the human race for the first few thousand years of its serious thinking.
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
I can deny my body and the world, but not my own existence [Descartes]
     Full Idea: I could pretend that I had no body, and that there was no world or place that I was in, but I could not, for all that, pretend that I did not exist.
     From: René Descartes (A Discourse on Method [1637], §4.32)
     A reaction: He makes the (in my opinion) appalling blunder of thinking that because he can pretend that he has no body, that therefore he might not have one. I can pretend that gold is an unusual form of cheese. However, "I don't exist" certainly sounds wrong.
Reason is universal in its responses, but a physical machine is constrained by its organs [Descartes]
     Full Idea: Whereas reason is a universal instrument which can serve on any kind of occasion, the organs of a machine need a disposition for each action; so it is impossible to have enough different organs in a machine to respond to all the occurrences of life.
     From: René Descartes (A Discourse on Method [1637], §5.57)
     A reaction: How can Descartes know that reason is 'universal' rather than just 'very extensive'? Is there any information which cannot be encoded in a computer? It doesn't feel as if there any intrinsic restrictions to reason, but note Idea 4688.
17. Mind and Body / A. Mind-Body Dualism / 2. Interactionism
The soul must unite with the body to have appetites and sensations [Descartes]
     Full Idea: It is not sufficient that the reasonable soul should be lodged in the body like a pilot in a ship, unless perhaps to move its limbs, but it needs to be united more closely with the body in order to have sensations and appetites, and so be a true man.
     From: René Descartes (A Discourse on Method [1637], §5.59)
     A reaction: The idea that the pineal gland is the link suggests that Descartes has the 'pilot' view, but this idea shows that he believes in very close and complex interaction between mind and body. But how can a mind 'have' appetites if it has no physical needs?
17. Mind and Body / E. Mind as Physical / 4. Connectionism
Perceptions could give us information without symbolic representation [Lyons]
     Full Idea: It is possible to give an account of concept-formation without a language of thought or representation, based on perception, which in the brain seems to involve information without representation.
     From: William Lyons (Approaches to Intentionality [1995], p.66)
     A reaction: This claim strikes me as being a little too confident. One might say that a concept IS a representation. However, the perception of several horses might 'blur' together to form a generalised horse.
18. Thought / A. Modes of Thought / 2. Propositional Attitudes
Propositional attitudes require representation [Lyons]
     Full Idea: How else, other than via some form of representational system, could a human organism contain information as a content over which it could operate or 'attitudinise'?
     From: William Lyons (Approaches to Intentionality [1995], Intro)
     A reaction: Depends what you mean by 'representational'. In its vaguest sense, this is just a tautology - content must be held in the mind in some form or other, but that tells us nothing.
18. Thought / A. Modes of Thought / 4. Folk Psychology
Folk psychology works badly for alien cultures [Lyons]
     Full Idea: It is not easy to employ our folk psychology in the understanding of persons in a very different culture.
     From: William Lyons (Approaches to Intentionality [1995], p.241)
     A reaction: This strikes me as a highly significant problem for the friends of folk psychology. It also breaks down in extreme situations, or with mental illness. It seems closer to culture than to brain structure.
18. Thought / B. Mechanics of Thought / 6. Artificial Thought / c. Turing Test
A machine could speak in response to physical stimulus, but not hold a conversation [Descartes]
     Full Idea: One may conceive of a machine made so as to emit words, and even emit them in response to a change in its bodily organs, such as being touched, but not to reply to the sense of everything said in its presence, as the most unintelligent men can.
     From: René Descartes (A Discourse on Method [1637], §5.56)
     A reaction: A critique of the Turing Test, written in 1637! You have to admire. Because of the advent of the microprocessor, we can 'conceive' more sophisticated, multi-level machines than Descartes could come up with.
18. Thought / C. Content / 1. Content
All thinking has content [Lyons]
     Full Idea: I cannot say I am simply thinking but not thinking about anything.
     From: William Lyons (Approaches to Intentionality [1995], Intro)
     A reaction: Hard to disagree. However, I can plausibly reply to 'What are you thinking?' with 'Nothing', if my consciousness is freewheeling. Utterly disconnected content isn't really what we call 'thinking'.
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Semantics should not be based on set-membership, but on instantiation of properties in objects [McGinn]
     Full Idea: Semantics should not employ the relationship of set-membership between objects and extensions, but rather the relation of instantiation between objects and properties.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: At least this means that philosophers won't be required to read fat books on set theory, but they will have to think very carefully about 'instantiation'. A good start is the ideas on 'Partaking' of Platonic Forms in this database (in 'Universals').
19. Language / C. Assigning Meanings / 7. Extensional Semantics
Clearly predicates have extensions (applicable objects), but are the extensions part of their meaning? [McGinn]
     Full Idea: We are taught that predicates have extensions - the class of objects of which the predicate is true - which seems hard to deny; but a stronger claim is also made - that extensions are semantically relevant features of predicates.
     From: Colin McGinn (Logical Properties [2000], Ch.3)
     A reaction: He cites Quine as a spokesman for this view. McGinn is going on to challenge it, by defending universals. It seems to fit in with other externalist theories of concepts and meanings, none of which seems very appealing to me.
23. Ethics / C. Virtue Theory / 1. Virtue Theory / d. Virtue theory critique
Greeks elevate virtues enormously, but never explain them [Descartes]
     Full Idea: The ancient pagans place virtues on a high plateau and make them appear the most valuable thing in the world, but they do not sufficiently instruct us about how to know them.
     From: René Descartes (A Discourse on Method [1637], §1.8)
26. Natural Theory / D. Laws of Nature / 7. Strictness of Laws
God has established laws throughout nature, and implanted ideas of them within us [Descartes]
     Full Idea: I have noticed certain laws that God has so established in nature, and of which he has implanted such notions in our souls, that …we cannot doubt that they are exactly observed in everything that exists or occurs in the world.
     From: René Descartes (A Discourse on Method [1637], pt 5), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 15.5
     A reaction: This is the view of laws which still seems to be with us (and needs extirpating) - that some outside agency imposes them on nature. I suspect that even Richard Feynman thought of laws like that, because he despised philosophy, and was thus naïve.
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
If Satan is the most imperfect conceivable being, he must have non-existence [McGinn]
     Full Idea: Satan cannot exist because he is the most imperfect conceivable being, and existence is one of the perfections.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: The logic of this seems right to me. Presumably the theologians would hastily deny this as a definition of Satan; he must have some positive qualities (like power) in order to enact his supreme moral imperfections. NIce, though.
I think the fault of the Ontological Argument is taking the original idea to be well-defined [McGinn]
     Full Idea: My own suspicion about the Ontological Argument is that the fault lies in taking notions like 'the most perfect, impressive and powerful being conceivable' to be well-defined.
     From: Colin McGinn (Logical Properties [2000], Ch.2)
     A reaction: I'm tempted to put it more strongly: the single greatest challenge for the theist with intellectual integrity is to give a clear and coherent definition of God. There must be no internal contradictions, and it must be within the bounds of possibility.