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All the ideas for 'Logical Properties', 'Of Human Freedom' and 'Principles of Philosophy'

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66 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
The greatest good for a state is true philosophers [Descartes]
     Full Idea: The greatest good which can exist in a state is to have true philosophers.
     From: René Descartes (Principles of Philosophy [1646], Pref)
     A reaction: …because they understand true reality, especially the Good.
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)
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 / 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 / 3. Being / c. Becoming
Being is only perceptible to itself as becoming [Schelling]
     Full Idea: Being is only perceptible to itself in the state of becoming.
     From: Friedrich Schelling (Of Human Freedom [1809], p.403), quoted by Jean-François Courtine - Schelling p.90
     A reaction: Is the Enlightenment the era of Being, and the Romantic era that of Becoming? They like process, fluidity, even chaos.
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.
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
All powers can be explained by obvious features like size, shape and motion of matter [Descartes]
     Full Idea: There are no powers in stones and plants that are not so mysterious that they cannot be explained …from principles that are known to all and admitted by all, namely the shape, size, position, and motion of particles of matter.
     From: René Descartes (Principles of Philosophy [1646], IV.187), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 23.6
     A reaction: This is an invocation of 'categorical' properties, against dispositions. I take this to be quite wrong. The explanation goes the other way. What supports the structures; what drives the motion; what initiates anything?
8. Modes of Existence / D. Universals / 1. Universals
Five universals: genus, species, difference, property, accident [Descartes]
     Full Idea: The five commonly enumerated universals are: genus, species, difference, property and accident.
     From: René Descartes (Principles of Philosophy [1646], I.59)
     A reaction: Interestingly, this seems to be Descartes passing on his medieval Aristotelian inheritance, in which things are defined by placing them in a class, and then noting what distinguishes them within that class.
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
A universal is a single idea applied to individual things that are similar to one another [Descartes]
     Full Idea: Universals arise solely from the fact that we avail ourselves of one idea in order to think of all individual things that have a certain similitude. When we understand under the same name all the objects represented by this idea, that name is universal.
     From: René Descartes (Principles of Philosophy [1646], I.59)
     A reaction: Judging by the boldness of the pronouncement, it looks as if Descartes hasn't recognised the complexity of the problem. How do we spot a 'similarity', especially an abstraction like 'tool' or 'useful'? This sounds like Descartes trying to avoid Platonism.
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
If we perceive an attribute, we infer the existence of some substance [Descartes]
     Full Idea: Based on perceiving the presence of some attribute, we conclude there must also be present an existing thing or substance to which it can be attributed.
     From: René Descartes (Principles of Philosophy [1646], I.52), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.1
     A reaction: A rainbow might be a tricky case. This illustrates the persistent belief in substances, even among philosophers who embraced the new corpuscular and mechanistic view of matter.
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
A substance needs nothing else in order to exist [Descartes]
     Full Idea: By substance we can understand nothing else than a thing which so exists that it needs no other thing in order to exist.
     From: René Descartes (Principles of Philosophy [1646], I.51)
     A reaction: Properties, of course, are the things which have dependent existence. Can properties be reduced to substances (e.g. by adopting a materialist theory of mind)? Note that Descartes does not think that substances depend on God for existence.
9. Objects / D. Essence of Objects / 9. Essence and Properties
A substance has one principal property which is its nature and essence [Descartes]
     Full Idea: Each substance has one principal property that constitutes its nature and essence, to which all its other properties are referred. Extension in length, breadth, and depth constitutes the nature of corporeal substance; and thought of thinking substances.
     From: René Descartes (Principles of Philosophy [1646], I.53), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.3
     A reaction: Property is likely to be 'propria', which is a property distinctive of some thing, not just any old modern property. This is quite a strikingly original view of the nature of essence. Descartes despised 'substantial forms'.
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 / B. Certain Knowledge / 4. The Cogito
Total doubt can't include your existence while doubting [Descartes]
     Full Idea: He who decides to doubt everything cannot nevertheless doubt that he exists while he doubts.
     From: René Descartes (Principles of Philosophy [1646], Pref)
I think, therefore I am, because for a thinking thing to not exist is a contradiction [Descartes]
     Full Idea: There is a contradiction in conceiving that what thinks does not (at the same time as it thinks) exist. Hence this conclusion I think, therefore I am, is the first and most certain that occurs to one who philosophises in an orderly way.
     From: René Descartes (Principles of Philosophy [1646], I.07)
     A reaction: The classic statement of his argument. The significance here is that it seems to have the structure of an argument, as it involves 'philosophising', which leads to a 'contradiction', and hence to the famous conclusion. It is not just intuitive.
'Thought' is all our conscious awareness, including feeling as well as understanding [Descartes]
     Full Idea: By the word 'thought' I understand everything we are conscious of as operating in us. And that is why not only understanding, willing, imagining, but also feeling, are here the same thing as thinking.
     From: René Descartes (Principles of Philosophy [1646], I.09)
     A reaction: There is a bit of tension here between Descartes' correct need to include feeling in thought for his Cogito argument, and his tendency to dismiss animal consciousness, on the grounds that they only sense things, and don't make judgements.
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / d. Absolute idealism
We must show that the whole of nature, because it is effective, is grounded in freedom [Schelling]
     Full Idea: What is required is to show that everything that is effective (nature, the world of things) is grounded in activity, life, freedom.
     From: Friedrich Schelling (Of Human Freedom [1809], p.351), quoted by Jean-François Courtine - Schelling
     A reaction: I take the ancestor of this view of nature to be the monads of Leibniz, as the active principle in nature. Because this is an idealist view, it starts with the absolute freedom of the Self, and presumably sees nature in its own image.
12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities
'Nothing comes from nothing' is an eternal truth found within the mind [Descartes]
     Full Idea: The proposition 'nothing comes from nothing' is not to be considered as an existing thing, or the mode of a thing, but as a certain eternal truth which has its seat in our mind and is a common notion or axiom.
     From: René Descartes (Principles of Philosophy [1646], I.49)
     A reaction: There is a tension here, in his assertion that it is 'eternal', but 'not existing'. How does one distinguish an innate idea from an innate truth? 'Eternal' sounds like an external guarantee of truth, but being 'in our mind' sounds less reliable.
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 / b. Basic beliefs
We can know basic Principles without further knowledge, but not the other way round [Descartes]
     Full Idea: It is on the Principles, or first causes, that the knowledge of other things depends, so the Principles can be known without these last, but the other things cannot reciprocally be known without the Principles.
     From: René Descartes (Principles of Philosophy [1646], Pref)
     A reaction: A particularly strong assertion of foundationalism, as it says that not only must the foundations exist, but also we must actually know them. This sounds false, as elementary knowledge then seems to require far too much sophistication.
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.
15. Nature of Minds / B. Features of Minds / 1. Consciousness / b. Essence of consciousness
We can understand thinking occuring without imagination or sensation [Descartes]
     Full Idea: We can understand thinking without imagination or sensation, as is quite clear to anyone who attends to the matter.
     From: René Descartes (Principles of Philosophy [1646], I.53)
     A reaction: We may certainly take it that Descartes means if it is understandable then it is logically possible. To believe that thinking could occur without imagination strikes me as an astonishing error. I take imagination to be more central than understanding.
16. Persons / D. Continuity of the Self / 7. Self and Thinking
In thinking we shut ourselves off from other substances, showing our identity and separateness [Descartes]
     Full Idea: Because each one of us understands what he thinks, and that in thinking he can shut himself off from every other substance, we may conclude that each of us is really distinct from every other thinking substance and from corporeal substance.
     From: René Descartes (Principles of Philosophy [1646], I.60)
     A reaction: This seems to be a novel argument which requires elucidation. I can 'shut myself off from every other substance'? If I shut myself off from thinking about food, does that mean hunger is not part of me? Or convince yourself that you don't have a brother?
16. Persons / F. Free Will / 1. Nature of Free Will
Our free will is so self-evident to us that it must be a basic innate idea [Descartes]
     Full Idea: It is so evident that we are possessed of a free will that can give or withhold its assent, that this may be counted as one of the first and most common notions found innately in us.
     From: René Descartes (Principles of Philosophy [1646], I.39)
     A reaction: It seems to me plausible to say that we have an innate conception of our own will (our ability to make decisions), though Hume says we only learn about the will from experience, but the idea that it is absolutely 'free' might never cross our minds.
16. Persons / F. Free Will / 2. Sources of Free Will
Only idealism has given us the genuine concept of freedom [Schelling]
     Full Idea: Until the discovery of idealism, the genuine concept of freedom has been missing from every modern system, whether it be that of Leibniz or of Spinoza.
     From: Friedrich Schelling (Of Human Freedom [1809], p.345), quoted by Jean-François Courtine - Schelling p.87
     A reaction: Spinoza denied free will, and Leibniz fudged it. Evidently more medieval theological accounts were not good enough. I presume Fichte is Schelling's hero, and he seems to see freedom as axiomatic about the Self.
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
There are two ultimate classes of existence: thinking substance and extended substance [Descartes]
     Full Idea: I observe two ultimate classes of things: intellectual or thinking things, pertaining to the mind or to thinking substance, and material things, pertaining to extended substance or to body.
     From: René Descartes (Principles of Philosophy [1646], I.48)
     A reaction: This is clear confirmation that Descartes believed the mind is a substance, rather than an insubstantial world of thinking. It leaves open the possibility of a different theory: that mind is not a substance, but is a Platonic adjunct to reality.
17. Mind and Body / D. Property Dualism / 5. Supervenience of mind
Even if tightly united, mind and body are different, as God could separate them [Descartes]
     Full Idea: Even if we suppose God had united a body and a soul so closely that they couldn't be closer, and made a single thing out of the two, they would still remain distinct, because God has the power of separating them, or conserving out without the other.
     From: René Descartes (Principles of Philosophy [1646], I.60)
     A reaction: If Descartes lost his belief in God (after discussing existence with Kant) would he cease to be a dualist? This quotation seems to be close to conceding a mind-body relationship more like supervenience than interaction.
18. Thought / A. Modes of Thought / 6. Judgement / b. Error
Most errors of judgement result from an inaccurate perception of the facts [Descartes]
     Full Idea: What usually misleads us is that we very frequently form a judgement although we do not have an accurate perception of what we judge.
     From: René Descartes (Principles of Philosophy [1646], I.33)
     A reaction: This seems to me a generally accurate observation, particularly in the making of moral judgements (which was probably not what Descartes was considering). The implication is that judgements are to a large extent forced by our perceptions.
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.
20. Action / C. Motives for Action / 4. Responsibility for Actions
We do not praise the acts of an efficient automaton, as their acts are necessary [Descartes]
     Full Idea: We do not praise automata, although they respond exactly to the movements they were designed to produce, since their actions are performed necessarily
     From: René Descartes (Principles of Philosophy [1646], I.37)
     A reaction: I say we attribute responsibility when we perceive something like a 'person' as causing them. We don't blame small animals, because there is 'no one at home', but we blame children as they develop a full character and identity. We can ignore free will.
The greatest perfection of man is to act by free will, and thus merit praise or blame [Descartes]
     Full Idea: That the will should extend widely accords with its nature, and it is the greatest perfection in man to be able to act by its means, that is, freely, and by so doing we are in peculiar way masters of our actions, and thereby merit praise or blame.
     From: René Descartes (Principles of Philosophy [1646], I.37)
     A reaction: This seems to me to be a deep-rooted and false understanding which philosophy has inherited from theology. It doesn't strike me that there must an absolute 'buck-stop' to make us responsible. Why is it better for a decision to appear out of nowhere?
26. Natural Theory / A. Speculations on Nature / 1. Nature
Physics only needs geometry or abstract mathematics, which can explain and demonstrate everything [Descartes]
     Full Idea: I do not accept or desire any other principle in physics than in geometry or abstract mathematics, because all the phenomena of nature may be explained by their means, and sure demonstrations can be given of them.
     From: René Descartes (Principles of Philosophy [1646], 2.64), quoted by Peter Alexander - Ideas, Qualities and Corpuscles 7
     A reaction: This is his famous and rather extreme view, which might be described as hyper-pythagoreanism (by adding geometry to numbers). It seems to leave out matter, forces and activity.
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / c. Purpose denied
We will not try to understand natural or divine ends, or final causes [Descartes]
     Full Idea: We will not seek for the reason of natural things from the end which God or nature has set before him in their creation .
     From: René Descartes (Principles of Philosophy [1646], §28)
     A reaction: Teleology is more relevant to biology than to the other sciences, and it is hard to understand an eye without a notion of 'what it is for'. Planetary motion reveals nothing about purposes. If you demand a purpose, it becomes more baffling.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension
Matter is not hard, heavy or coloured, but merely extended in space [Descartes]
     Full Idea: The nature of matter, or body viewed as a whole, consists not in its being something which is hard, heavy, or colored, or which in any other way affects the senses, but only in its being a thing extended in length, breadth and depth.
     From: René Descartes (Principles of Philosophy [1646], 2.4), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 04.5
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.