16 ideas
| 9108 | From an impossibility anything follows [William of Ockham] |
| Full Idea: From an impossibility anything follows ('quod ex impossibili sequitur quodlibet'). | |
| From: William of Ockham (Summa totius logicae [1323], III.c.xxxvi) | |
| A reaction: The hallmark of a true logician, I suspect, is that this opinion is really meaningful and important to them. They yearn to follow the logic wherever it leads. Common sense would seem to say that absolutely nothing follows from an impossibility. |
| 9107 | A proposition is true if its subject and predicate stand for the same thing [William of Ockham] |
| Full Idea: If in the proposition 'This is an angel' subject and predicate stand for the same thing, the proposition is true. | |
| From: William of Ockham (Summa totius logicae [1323], II.c.ii) | |
| A reaction: An interesting statement of what looks like a correspondence theory, employing the idea that both the subject and the predicate have a reference. I think Frege would say that 'x is an angel' is unsaturated, and so lacks reference. |
| 16300 | Ockham had an early axiomatic account of truth [William of Ockham, by Halbach] |
| Full Idea: Theories structurally very similar to axiomatic compositional theories of truth can be found in Ockham's 'Summa Logicae'. | |
| From: report of William of Ockham (Summa totius logicae [1323]) by Volker Halbach - Axiomatic Theories of Truth 3 |
| 13591 | Quantified modal logic collapses if essence is withdrawn [Quine] |
| Full Idea: The whole of quantified modal logic collapses if essence is withdrawn. | |
| From: Willard Quine (Intensions Revisited [1977], p.121) | |
| A reaction: Quine offers an interesting qualification to this crushing remark in Idea 13590. The point is that objects must retain their identity in modal contexts, as if I say 'John Kennedy might have been Richard Nixon'. What could that mean? |
| 9106 | The word 'every' only signifies when added to a term such as 'man', referring to all men [William of Ockham] |
| Full Idea: The syncategorematic word 'every' does not signify any fixed thing, but when added to 'man' it makes the term 'man' stand for all men actually. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.iv) | |
| A reaction: Although quantifiers may have become a part of formal logic with Frege, their importance is seen from Aristotle onwards, and it is clearly a key part of William's understanding of logic. |
| 9113 | Just as unity is not a property of a single thing, so numbers are not properties of many things [William of Ockham] |
| Full Idea: Number is nothing but the actual numbered things themselves. Hence just as unity is not an accident added to the thing which is one, so number is not an accident of the things which are numbered. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.xliv) | |
| A reaction: [William does not necessarily agree with this view] It strikes me as a key point here that any account of the numbers had better work for 'one', though 'zero' might be treated differently. Some people seem to think unity is a property of things. |
| 9110 | The words 'thing' and 'to be' assert the same idea, as a noun and as a verb [William of Ockham] |
| Full Idea: The words 'thing' and 'to be' (esse) signify one and the same thing, but the one in the manner of a noun and the other in the manner of a verb. | |
| From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
| A reaction: Well said - as you would expect from a thoroughgoing nominalist. I would have thought that this was the last word on the subject of Being, thus rendering any need for me to read Heidegger quite superfluous. Or am I missing something? |
| 15388 | Universals are single things, and only universal in what they signify [William of Ockham] |
| Full Idea: Every universal is one particular thing and it is not a universal except in its signification, in its signifying many thing. | |
| From: William of Ockham (Summa totius logicae [1323]), quoted by Claude Panaccio - Medieval Problem of Universals 'William' | |
| A reaction: Sounds as if William might have liked tropes. It seems to leave the problem unanswered (the 'ostrich' problem?). How are they able to signify in this universal way, if each thing is just distinct and particular? |
| 9109 | If essence and existence were two things, one could exist without the other, which is impossible [William of Ockham] |
| Full Idea: If essence and existence were two things, then no contradiction would be involved if God preserved the essence of a thing in the world without its existence, or vice versa, its existence without its essence; both of which are impossible. | |
| From: William of Ockham (Summa totius logicae [1323], III,II,c,xxvii) | |
| A reaction: Not that William is using the concept of a supreme mind as a tool in argument. His denial of essence as something separable is presumably his denial of the Aristotelian view of universals, as well as of the Platonic view. |
| 13590 | Essences can make sense in a particular context or enquiry, as the most basic predicates [Quine] |
| Full Idea: The notion of essence makes sense in context. Relative to a particular enquiry, some predicates may play a more basic role than others, or may apply more fixedly; and these may be treated as essential. | |
| From: Willard Quine (Intensions Revisited [1977], p.121) | |
| A reaction: Quine has got a bad press on essentialism, and on modal logic, but I take this point seriously. If you give something a fixed identity by means of essence in some context, you can then go ahead and apply possible world reasoning in that context. |
| 8483 | Necessity is relative to context; it is what is assumed in an inquiry [Quine] |
| Full Idea: The very notion of necessity makes sense to me only relative to context. Typically it is applied to what is assumed in an inquiry, as against what has yet to transpire. | |
| From: Willard Quine (Intensions Revisited [1977], p.121) | |
| A reaction: Lots of things are assumed by an inquiry without an assumption that they must be true. Quine is the greatest opponent of necessity in all of philosophy. Asserting necessities, though, is too much fun to give up. It would ruin philosophy. |
| 13589 | Possible worlds are a way to dramatise essentialism, and yet they presuppose essentialism [Quine] |
| Full Idea: Talk of possible worlds is a graphic way of waging the essentialist philosophy, but it is only that; it is not an explication. Essence is needed to identify an object from one possible world to another. | |
| From: Willard Quine (Intensions Revisited [1977], p.118) | |
| A reaction: He makes the proposal sound circular, but I take a commitment to essences to be prior to talk of possible worlds. Possible worlds are a tool for clarifying modalities, not for clarifying essential identities. |
| 13588 | A rigid designator (for all possible worlds) picks out an object by its essential traits [Quine] |
| Full Idea: A rigid designator differs from others in that it picks out its object by essential traits. It designates the object in all possible worlds in which it exists. | |
| From: Willard Quine (Intensions Revisited [1977], p.118) | |
| A reaction: This states the point more clearly than Kripke ever does, and I presume it is right. Thus when we say that we wish 'our' Hubert Humphrey had won the election, we can allow that his victory elation would change him a bit. Kripke is right. |
| 13592 | Beliefs can be ascribed to machines [Quine] |
| Full Idea: Beliefs have been ascribed to machines, in support of a mechanistic philosophy, and I share this attitude. | |
| From: Willard Quine (Intensions Revisited [1977], p.123) | |
| A reaction: [He cites Raymond Nelson] One suspects that this is Quine's latent behaviourism speaking. It strikes me as a crass misuse of 'belief' to ascribe it to a simple machine like a thermostat. |
| 9105 | Some concepts for propositions exist only in the mind, and in no language [William of Ockham] |
| Full Idea: Conceptual terms and the propositions formed by them are those mental words which do not belong to any language; they remain only in the mind and cannot be uttered exteriorly, though signs subordinated to these can be exteriorly uttered. | |
| From: William of Ockham (Summa totius logicae [1323], I.c.i) | |
| A reaction: [He cites Augustine] A glimmer of the idea of Mentalese, and is probably an integral part of any commitment to propositions. Quine would hate it, but I like it. Logicians seem to dislike anything that cannot be articulated, but brains are like that. |
| 7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
| Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom. | |
| From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88) | |
| A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate'). |