10 ideas
| 13591 | Quantified modal logic collapses if essence is withdrawn [Quine] |
| Full Idea: The whole of quantified modal logic collapses if essence is withdrawn.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? |
| 19347 | Substance needs independence, unity, and stability (for individuation); also it is a subject, for predicates [Perkins] |
| Full Idea: For individuation, substance needs three properties: independence, to separate it from other things; unity, to call it one thing, rather than an aggregate; and permanence or stability over time. Its other role is as subject for predicates. | |
| From: Franklin Perkins (Leibniz: Guide for the Perplexed [2007], 3.1) | |
| A reaction: Perkins is describing the Aristotelian view, which is taken up by Leibniz. 'Substance' is not a controversial idea, if we see that it only means that the world is full of 'things'. It is an unusual philosopher wholly totally denies that. |
| 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. |
| 7880 | If a blind persons suddenly sees a kestrel, that doesn't make visual and theoretical kestrels different [Papineau on Jackson] |
| Full Idea: An ornithological Mary might know everything theoretical about kestrels, but be blind from birth, then have her sight restored. She now knows "That bird eats mice", so visual kestrels must be ontologically distinct from theoretical ones. | |
| From: comment on Frank Jackson (Epiphenomenal Qualia [1982]) by David Papineau - Thinking about Consciousness 6.3 | |
| A reaction: A nice reductio, and I think this pinpoints best what is wrong with the knowledge argument. Knowledge, and the means of acquiring it, are two distinct things. When I see x, I don't acquire knowledge of x, AND knowledge of my seeing x. |
| 7378 | No one bothers to imagine what it would really be like to have ALL the physical information [Dennett on Jackson] |
| Full Idea: That Mary "has all the physical information" is not readily imaginable, so no one bothers. They just imagine she knows lots and lots - perhaps everything known today - but that is just a drop in the bucket. | |
| From: comment on Frank Jackson (Epiphenomenal Qualia [1982]) by Daniel C. Dennett - Consciousness Explained 12.5 | |
| A reaction: I certainly don't see how we can rule out a priori the possibility that someone who really had all the physical knowledge might be able to infer the phenomenal properties of colour. |
| 7377 | Mary learns when she sees colour, so her complete physical information had missed something [Jackson] |
| Full Idea: It seems obvious that Mary will learn something about the world when she is released from her black-and-white room; but then it is inescapable that her previous knowledge was incomplete; she had all the physical information, so there is more to have. | |
| From: Frank Jackson (Epiphenomenal Qualia [1982], §1) | |
| A reaction: This is Jackson's famous 'knowledge argument', which seems to me misconceived. Since I don't think phenomenal colours are properties of objects (Idea 5456), Mary learns more about herself, and about her means of acquiring knowledge. |