11 ideas
| 11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
| Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], II) | |
| A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts. |
| 11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
| Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table. | |
| From: Ian Rumfitt ("Yes" and "No" [2000]) | |
| A reaction: This is the standard view which Rumfitt sets out to challenge. |
| 11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
| Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], III) | |
| A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value. |
| 3296 | Sense-data are a false objectification of what is essentially subjective [Nagel] |
| Full Idea: The private object or sense datum view is an instance of the false objectification of what is essentially subjective. | |
| From: Thomas Nagel (Subjective and Objective [1979], p.207) |
| 3295 | Inner v outer brings astonishment that we are a particular person [Nagel] |
| Full Idea: The problem of reconciling the objective and subjective points of view takes its purest form in a sense of incredulity that one should be anyone in particular. | |
| From: Thomas Nagel (Subjective and Objective [1979], p.206) | |
| A reaction: Nice observation. This idea has always struck me forcibly, and seems to be one of those basic intuitions which motivates philosophy, and yet the subject has almost nothing to say about it. Of course you are you, or you wouldn't be amazed by it… |
| 3293 | If you assert that we have an ego, you can still ask if that future ego will be me [Nagel] |
| Full Idea: The metaphysical ego, if it is a continuing individual with its identity over time, is just one more thing about which the same problem can be raised - will that ego still be me? | |
| From: Thomas Nagel (Subjective and Objective [1979], p.200) | |
| A reaction: You can worry too much about some philosophical questions. If it is me now, and it has continuing individual identity over time, I'm not going to lose sleep over the possibility that it might nevertheless somehow cease to be me. I'm overrated. |
| 3292 | The most difficult problem of free will is saying what the problem is [Nagel] |
| Full Idea: The most difficult problem of free will is saying what the problem is. | |
| From: Thomas Nagel (Subjective and Objective [1979], p.198) |
| 2596 | Maybe mind and body are parallel, like two good clocks [Leibniz] |
| Full Idea: Two clocks in perfect agreement must be by natural influence, or the control of a craftsman, or their perfect construction at the beginning. Only the third way (of "preestablished harmony" by God) is possible. | |
| From: Gottfried Leibniz (The Nature and Communication of Substance [1690], p.121) | |
| A reaction: Presumably 'natural influence' would cover the possibility that (unnoticed by you, apparently) one clock is attached to the other clock at the relevant points. If they are unconnected, presumably they are quite unaware of one another's existence. |
| 11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
| Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A. | |
| From: Ian Rumfitt ("Yes" and "No" [2000], IV) | |
| A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role). |
| 3294 | As far as possible we should become instruments to realise what is best from an eternal point of view [Nagel] |
| Full Idea: The right thing to do is to turn oneself as far as possible into an instrument for the realisation of what is best 'sub specie aeternitatis'. | |
| From: Thomas Nagel (Subjective and Objective [1979], p.204) |
| 2595 | If the universe is a perfect agreement of uncommunicating substances, there must be a common source [Leibniz] |
| Full Idea: The perfect agreement of so many substances which have no communication whatever with each other can only come from a common source. | |
| From: Gottfried Leibniz (The Nature and Communication of Substance [1690], p.120) |