90 ideas
23890 | For Plato true wisdom is supernatural [Plato, by Weil] |
Full Idea: It is evident that Plato regards true wisdom as something supernatural. | |
From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.61 | |
A reaction: Taken literally, I assume this is wrong, but we can empathise with the thought. Wisdom has the feeling of rising above the level of mere knowledge, to achieve the overview I associate with philosophy. |
3060 | Plato never mentions Democritus, and wished to burn his books [Plato, by Diog. Laertius] |
Full Idea: Plato, who mentions nearly all the ancient philosophers, nowhere speaks of Democritus; he wished to burn all of his books, but was persuaded that it was futile. | |
From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.7.8 |
23891 | Two contradictories force us to find a relation which will correlate them [Plato, by Weil] |
Full Idea: Where contradictions appear there is a correlation of contraries, which is relation. If a contradiction is imposed on the intelligence, it is forced to think of a relation to transform the contradiction into a correlation, which draws the soul higher. | |
From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.70 | |
A reaction: A much better account of the dialectic than anything I have yet seen in Hegel. For the first time I see some sense in it. A contradiction is not a falsehood, and it must be addressed rather than side-stepped. A kink in the system, that needs ironing. |
6052 | 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. |
6064 | 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) |
6088 | 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. |
6084 | '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. |
6085 | 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. |
6083 | 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. |
6086 | 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. |
6087 | 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'? |
6051 | 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? |
6055 | 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. |
6059 | 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. |
6042 | 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. |
6067 | 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. |
6069 | '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. |
6068 | 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. |
6070 | 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. |
6062 | 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. |
6065 | 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? |
6082 | 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'. |
6075 | 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. |
14502 | Plato's idea of 'structure' tends to be mathematically expressed [Plato, by Koslicki] |
Full Idea: 'Structure' tends to be characterized by Plato as something that is mathematically expressed. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects V.3 iv | |
A reaction: [Koslicki is drawing on Verity Harte here] |
3039 | When Diogenes said he could only see objects but not their forms, Plato said it was because he had eyes but no intellect [Plato, by Diog. Laertius] |
Full Idea: When Diogenes told Plato he saw tables and cups, but not 'tableness' and 'cupness', Plato replied that this was because Diogenes had eyes but no intellect. | |
From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 06.2.6 |
17948 | Plato's Forms meant that the sophists only taught the appearance of wisdom and virtue [Plato, by Nehamas] |
Full Idea: Plato's theory of Forms allowed him to claim that the sophists and other opponents were trapped in the world of appearance. What they therefore taught was only apparent wisdom and virtue. | |
From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.118 |
20906 | Platonists argue for the indivisible triangle-in-itself [Plato, by Aristotle] |
Full Idea: The Platonists, on the basis of purely logical arguments, posit the existence of an indivisible 'triangle in itself'. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 316a15 | |
A reaction: A helpful confirmation that geometrical figures really are among the Forms (bearing in mind that numbers are not, because they contain one another). What shape is the Form of the triangle? |
556 | If there is one Form for both the Form and its participants, they must have something in common [Aristotle on Plato] |
Full Idea: If there is the same Form for the Forms and for their participants, then they must have something in common. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a |
563 | If gods are like men, they are just eternal men; similarly, Forms must differ from particulars [Aristotle on Plato] |
Full Idea: We say there is the form of man, horse and health, but nothing else, making the same mistake as those who say that there are gods but that they are in the form of men. They just posit eternal men, and here we are not positing forms but eternal sensibles. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 997b |
565 | The Forms cannot be changeless if they are in changing things [Aristotle on Plato] |
Full Idea: The Forms could not be changeless if they were in changing things. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 998a |
557 | A Form is a cause of things only in the way that white mixed with white is a cause [Aristotle on Plato] |
Full Idea: A Form is a cause of things only in the way that white mixed with white is a cause. | |
From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a |
9607 | The greatest discovery in human thought is Plato's discovery of abstract objects [Brown,JR on Plato] |
Full Idea: The greatest discovery in the history of human thought is Plato's discovery of abstract objects. | |
From: comment on Plato (works [c.375 BCE]) by James Robert Brown - Philosophy of Mathematics Ch. 2 | |
A reaction: Compare Idea 2860! Given the diametrically opposed views, it is clearly likely that Plato's central view is the most important idea in the history of human thought, even if it is wrong. |
13263 | We can grasp whole things in science, because they have a mathematics and a teleology [Plato, by Koslicki] |
Full Idea: Due to the mathematical nature of structure and the teleological cause underlying the creation of Platonic wholes, these wholes are intelligible, and are in fact the proper objects of science. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3 | |
A reaction: I like this idea, because it pays attention to the connection between how we conceive objects to be, and how we are able to think about objects. Only examining these two together enables us to grasp metaphysics. |
13261 | Plato sees an object's structure as expressible in mathematics [Plato, by Koslicki] |
Full Idea: The 'structure' of an object tends to be characterised by Plato as something that is mathematically expressible. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3 | |
A reaction: This seems to be pure Pythagoreanism (see Idea 644). Plato is pursuing Pythagoras's research programme, of trying to find mathematics buried in every aspect of reality. |
13265 | Plato was less concerned than Aristotle with the source of unity in a complex object [Plato, by Koslicki] |
Full Idea: Plato was less concerned than Aristotle with the project of how to account, in completely general terms, for the source of unity within a mereologically complex object. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.5 | |
A reaction: Plato seems to have simply asserted that some sort of harmony held things together. Aristotles puts the forms [eidos] within objects, rather than external, so he has to give a fuller account of what is going on in an object. He never managed it! |
593 | Plato's holds that there are three substances: Forms, mathematical entities, and perceptible bodies [Plato, by Aristotle] |
Full Idea: Plato's doctrine was that the Forms and mathematicals are two substances and that the third substance is that of perceptible bodies. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Metaphysics 1028b |
13260 | Plato says wholes are either containers, or they're atomic, or they don't exist [Plato, by Koslicki] |
Full Idea: Plato considers a 'container' model for wholes (which are disjoint from their parts) [Parm 144e3-], and a 'nihilist' model, in which only wholes are mereological atoms, and a 'bare pluralities' view, in which wholes are not really one at all. | |
From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.2 | |
A reaction: [She cites Verity Harte for this analysis of Plato] The fourth, and best, seems to be that wholes are parts which fall under some unifying force or structure or principle. |
22744 | Parts are not parts if their whole is nothing more than the parts [Sext.Empiricus] |
Full Idea: If the whole is nothing more than the sum of the parts, the parts will not be parts. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.343) | |
A reaction: Nice. Bricks lying on the ground are not parts of a wall. For them to be parts of a wall there has to be a wall which is not just the bricks. Nihilists like Van Inwagen can deny the wall in ontology, but in thought we need walls. Conceptual dependence. |
11237 | Only universals have essence [Plato, by Politis] |
Full Idea: Plato argues that only universals have essence. | |
From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4 |
11238 | Plato and Aristotle take essence to make a thing what it is [Plato, by Politis] |
Full Idea: Plato and Aristotle have a shared general conception of essence: the essence of a thing is what that thing is simply in virtue of itself and in virtue of being the very thing it is. It answers the question 'What is this very thing?' | |
From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4 |
6058 | 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! |
6053 | 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. |
6043 | 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). |
6044 | 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. |
6046 | 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). |
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). |
6066 | 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. |
6054 | 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. |
6047 | 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). |
6049 | 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. |
6048 | 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'). |
6050 | 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… |
6080 | 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. |
6079 | 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. |
22748 | Some say motion is perceived by sense, but others say it is by intellect [Sext.Empiricus] |
Full Idea: Some assert that motion is perceived by sense, but others that it is not perceived at all by sense but by the intellect through sensation. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.062) | |
A reaction: Descartes' wax argument defends the idea that change is perceived by intellect. The intellect has to distinguish the relative aspect of each motion, such as when someone is walking around on a moving ship. Even sense also need memory. |
6081 | 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. |
6071 | 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. |
17085 | A good explanation totally rules out the opposite explanation (so Forms are required) [Plato, by Ruben] |
Full Idea: For Plato, an acceptable explanation is one such that there is no possibility of there being the opposite explanation at all, and he thought that only explanations in terms of the Forms, but never physical explanations, could meet this requirement. | |
From: report of Plato (works [c.375 BCE]) by David-Hillel Ruben - Explaining Explanation Ch 2 | |
A reaction: [Republic 436c is cited] |
22746 | If we try to conceive of a line with no breadth, it ceases to exist, and so has no length [Sext.Empiricus] |
Full Idea: When we have gone so far as to deprive the length of its breadth altogether, we no longer conceive even the length, but along with the removal of the breadth the conception of the length is also removed. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.392) | |
A reaction: The only explanation of our retaining an understanding of a line even after we have removed its breadth is that we have abandoned experience and conceptualised the line - by idealising it. |
22741 | The incorporeal is not in the nature of body, and so could not emerge from it [Sext.Empiricus] |
Full Idea: The incorporeal will never come into existence from body because the nature of the incorporeal does not exist in body. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.225) | |
A reaction: So nothing high could be made of pebbles because pebbles are not high? His argument depends on incorporeality having an intrinsically incorporeal nature. Pebbles have some height which can be extended. |
1651 | Plato wanted to somehow control and purify the passions [Vlastos on Plato] |
Full Idea: Plato put high on his agenda a project which did not figure in Socrates' programme at all: the hygienic conditioning of the passions. This cannot be an intellectual process, as argument cannot touch them. | |
From: comment on Plato (works [c.375 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.88 | |
A reaction: This is the standard traditional view of any thinker who exaggerates the importance and potential of reason in our lives. |
6077 | 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'). |
6074 | 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. |
3324 | Plato's whole philosophy may be based on being duped by reification - a figure of speech [Benardete,JA on Plato] |
Full Idea: Plato is liable to the charge of having been duped by a figure of speech, albeit the most profound of all, the trope of reification. | |
From: comment on Plato (works [c.375 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.12 | |
A reaction: That might be a plausible account if his view was ridiculous, but given how many powerful friends Plato has, especially in the philosophy of mathematics, we should assume he was cleverer than that. |
7503 | Plato never refers to examining the conscience [Plato, by Foucault] |
Full Idea: Plato never speaks of the examination of conscience - never! | |
From: report of Plato (works [c.375 BCE]) by Michel Foucault - On the Genealogy of Ethics p.276 | |
A reaction: Plato does imply some sort of self-evident direct knowledge about that nature of a healthy soul. Presumably the full-blown concept of conscience is something given from outside, from God. In 'Euthyphro', Plato asserts the primacy of morality (Idea 337). |
2173 | As religion and convention collapsed, Plato sought morals not just in knowledge, but in the soul [Williams,B on Plato] |
Full Idea: Once gods and fate and social expectation were no longer there, Plato felt it necessary to discover ethics inside human nature, not just as ethical knowledge (Socrates' view), but in the structure of the soul. | |
From: comment on Plato (works [c.375 BCE]) by Bernard Williams - Shame and Necessity II - p.43 | |
A reaction: anti Charles Taylor |
9274 | Plato's legacy to European thought was the Good, the Beautiful and the True [Plato, by Gray] |
Full Idea: Plato's legacy to European thought was a trio of capital letters - the Good, the Beautiful and the True. | |
From: report of Plato (works [c.375 BCE]) by John Gray - Straw Dogs 2.8 | |
A reaction: It seems to have been Baumgarten who turned this into a slogan (Idea 8117). Gray says these ideals are lethal, but I identify with them very strongly, and am quite happy to see the good life as an attempt to find the right balance between them. |
94 | Pleasure is better with the addition of intelligence, so pleasure is not the good [Plato, by Aristotle] |
Full Idea: Plato says the life of pleasure is more desirable with the addition of intelligence, and if the combination is better, pleasure is not the good. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Nicomachean Ethics 1172b27 | |
A reaction: It is obvious why we like pleasure, but not why intelligence makes it 'better'. Maybe it is just because we enjoy intelligence? |
17947 | Plato decided that the virtuous and happy life was the philosophical life [Plato, by Nehamas] |
Full Idea: Plato came to the conclusion that virtue and happiness consist in the life of philosophy itself. | |
From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.117 | |
A reaction: This view is obviously ridiculous, because it largely excludes almost the entire human race, which sees philosophy as a cul-de-sac, even if it is good. But virtue and happiness need some serious thought. |
6015 | Plato, unusually, said that theoretical and practical wisdom are inseparable [Plato, by Kraut] |
Full Idea: Two virtues that are ordinarily kept distinct - theoretical and practical wisdom - are joined by Plato; he thinks that neither one can be fully possessed unless it is combined with the other. | |
From: report of Plato (works [c.375 BCE]) by Richard Kraut - Plato | |
A reaction: I get the impression that this doctrine comes from Socrates, whose position is widely reported as 'intellectualist'. Aristotle certainly held the opposite view. |
2912 | Plato is boring [Nietzsche on Plato] |
Full Idea: Plato is boring. | |
From: comment on Plato (works [c.375 BCE]) by Friedrich Nietzsche - Twilight of the Idols 9.2 |
22747 | A man walking backwards on a forwards-moving ship is moving in a fixed place [Sext.Empiricus] |
Full Idea: If a ship moves forward and a man carries a rod backwards on it, then it is possible for an object to move without quitting its place. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.056) | |
A reaction: [summary of a verbose paragraph] The point is that you cannot define movement as change of place (contrary to Russell's proposal!). The concept of a place seems to be relative. Walking on a treadmill. |
22749 | Time doesn't end with the Universe, because tensed statements about destruction remain true [Sext.Empiricus] |
Full Idea: It is absurd to say that when the Universe is destroyed time does not exist; for the statement that it was destroyed once and that it is being destroyed are indicative of times. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.188) | |
A reaction: Intriguing. He takes it that a proposition can be true even though nothing exists. This is not merely an affirmation of the tensed A-series view of time, but he even offers tenses as evidence that the A-series is correct. That time could cease was a view. |
1526 | Almost everyone except Plato thinks that time could not have been generated [Plato, by Aristotle] |
Full Idea: With a single exception (Plato) everyone agrees about time - that it is not generated. Democritus says time is an obvious example of something not generated. | |
From: report of Plato (works [c.375 BCE]) by Aristotle - Physics 251b14 |
22750 | Time is divisible, into past, present and future [Sext.Empiricus] |
Full Idea: Time cannot be indivisible, since it is divided into past, present and future. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.193) | |
A reaction: Does the fact that you can name the parts of something prove that it is divisible? Do electrons have left and right-hand sides? |
22742 | Socrates either dies when he exists (before his death) or when he doesn't (after his death) [Sext.Empiricus] |
Full Idea: Socrates either dies when existing, or when not existing. …He does not die when he exists, for he is alive, and he does not die when he has died, for then he will be dying twice, which is absurd. So then, Socrates does not die. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.269) | |
A reaction: A nice dramatisation of a major dilemma. The present moment is just the boundary between the past and the future, and so has no magnitude, and hence nothing can occur during the present. Perhaps my favourite philosophical dilemma. |
22751 | If the present is just the limit of the past or the future, it can't exist because they don't exist [Sext.Empiricus] |
Full Idea: If the present is the limit of the past, and the limit of the past has passed away together with that of which it is the limit, the present no longer exists. And if the present begins the future, which doesn't exist, the present does not yet exist. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], II.201) | |
A reaction: If I mark a line on the ground where the wall will begin, the limit seems prior to the object. The gun starts the race, but is not part of it. That said, I cannot think of any more mysterious entity than the present moment. It isn't a line or a bang. |
22730 | All men agree that God is blessed, imperishable, happy and good [Sext.Empiricus] |
Full Idea: All men have one common preconception about God, according to which he is a blessed creature and imperishable and perfect in happiness and receptive of nothing evil. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.033) | |
A reaction: He observes this after he has pointed the enormous variety of religious beliefs. He offers this unanimity as a reason to believe that it is true. |
22739 | God must suffer to understand suffering [Sext.Empiricus] |
Full Idea: God cannot have a notion of suffering if he has not experience it. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.163) | |
A reaction: Christians like to portray God as suffering because of his son's horrible death. We can imagine experiences we have never had, and presumably God is better at that than we are. |
22738 | The Divine must lack the virtues of continence and fortitude, because they are not needed [Sext.Empiricus] |
Full Idea: If the Divine is all-virtuous, it possesses all the virtues. But it does not possess the virtues of continence and fortitude unless there are certain things which are hard for God to abstain from and hard to endure. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.151) | |
A reaction: Courage would also be unnecessary, we assume. Good people are not tempted to steal, and hence do not need to resist it. It is a mistake to attribute human virtues to the Divine. Humans lack the virtues of a good frog. |
22734 | God is defended by agreement, order, absurdity of denying God, and refutations [Sext.Empiricus] |
Full Idea: Arguments for God have four modes: from universal agreement, from the orderly arrangement of the universe, from the absurd consequences of denying God, and from undermining the opposing arguments. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.060) | |
A reaction: [compressed] The loss of status of the argument from universal agreement has had a huge influence. We now realise that a very wide consensus is no guarantee of truth in anything. |
22736 | God's sensations imply change, and hence perishing, which is absurd, so there is no such God [Sext.Empiricus] |
Full Idea: If God has sensation he is altered, …so he is receptive of change, including change for the worse. If so, he is also perishable, but that is absurd; therefore it is absurd also to claim that God exists. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.146) | |
A reaction: [compressed] It is certainly paradoxical to think that God is eternal and unchanging, but also capable of perception and thought, which necessitate change. Some theological ingenuity is needed to explain this. |
22740 | God without virtue is absurd, but God's virtues will be better than God [Sext.Empiricus] |
Full Idea: If the Divine exists it either has or has not virtue. If it has not it is base and unhappy, which is absurd. But if it has it, there will exist something which is better than God, just as a virtue of a horse is better than the horse itself. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.176) | |
A reaction: It is obviously better to think of a virtue as some mode of a thing, rather than as a separate attachment. This is an ontological argument, because it is inferred from the concept of God. |
6072 | 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. |
6073 | 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. |
22735 | The original substance lacked motion or shape, and was given these by a cause [Sext.Empiricus] |
Full Idea: They say that the substance of existing things being of itself motionless and shapeless must be put in motion and shape by some cause. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.075) | |
A reaction: Interestingly, Sextus doesn't seem to think that the existence of the original substance also needs a cause. This substance sounds like a relative of Aristotle's Prime Matter. The source of motion isn't really a 'design' argument. |
22732 | The perfections of God were extrapolations from mankind [Sext.Empiricus] |
Full Idea: It is said that …the idea that God is eternal and imperishable and perfect in happiness was introduced by way of transference from mankind. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.045) | |
A reaction: This view is found in Hume, and in Feuerbach. I presume 'transference' means extrapolation and idealisation. If God exists, we may have no option but to think of God anthropomorphically. |
22728 | Gods were invented as watchers of people's secret actions [Sext.Empiricus] |
Full Idea: It is asserted that those who first led mankind …invented gods as watchers of all the sinful and righteous acts of men, so that none should dare to do wrong even in secret. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.016) | |
A reaction: Sextus is a sceptic about everything, so this scepticism about the gods is nothing special. I'm not sure if this is why the gods were invented, but it seems to be the main role assigned to God by the Christian church, as the basis of religious morality. |
22737 | An incorporeal God could do nothing, and a bodily god would perish, so there is no God [Sext.Empiricus] |
Full Idea: The Divine is not incorporeal, since that is inanimate and insensitive and incapable of any action; nor is it a body, since that is subject to change and perishable; so the Divine does not exist. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.151) | |
A reaction: I find this quite persuasive. An incorporeal God has to be ascribed magical powers in order to interact with what is corporeal. A corporeal God is subject to entropy and all the depredations of the physical world. |
22731 | It is mad to think that what is useful to us, like lakes and rivers, are gods [Sext.Empiricus] |
Full Idea: To suppose that lakes and rivers, and whatsoever else is of a nature to be useful to us, are gods surpasses the height of lunacy. | |
From: Sextus Empiricus (Against the Physicists (two books) [c.180], I.040) | |
A reaction: He also points out the what is useful to us decays and changes. Sextus lived in a time when monotheism was becoming dominant. |