15 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. |
| 16066 | Additional or removal of any part changes a thing, so people are never the same person [Epicharmus] |
| Full Idea: If you add or take away a pebble, the same number does not remain. If you add to a length or cut off from it, the former measure does not remain. So human beings grow or waste away. Both you and I were, and shall be, other men. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B02), quoted by Diogenes Laertius - Lives of Eminent Philosophers 03.12 | |
| A reaction: [The original is in dialogue form from a play. The context is a joke about not paying a debt.] Note the early date for this metaphysical puzzle. My new favourite reply is Chrysippus's Idea 16059; identity actually requires change. |
| 436 | A dog seems handsome to another a dog, and even a pig to another pig [Epicharmus] |
| Full Idea: Dog seems very handsome to dog, and ox to ox, and donkey very handsome to donkey, and even pig to pig. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B05), quoted by (who?) - where? |
| 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). |
| 4581 | Virtues and vices are like secondary qualities in perception, found in observers, not objects [Hume] |
| Full Idea: Vice and virtue may be compared to sounds, colours, heat and cold, which, according to modern philosophy, are not qualities in objects but perceptions in the mind. | |
| From: David Hume (Letters [1739], to Hutcheson 1740) | |
| A reaction: Very revealing about the origin of the is/ought idea, but this is an assertion rather than an argument. Most Greeks treat value as a primary quality of things (e.g. life, harmony, beauty, health). |
| 442 | Pleasures are like pirates - if you are caught they drown you in a sea of pleasures [Epicharmus] |
| Full Idea: Pleasures for mortals are like impious pirates, for the man who is caught by pleasures is immediately drowned in a sea of them. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B44), quoted by (who?) - where? | |
| A reaction: Not all slopes are slippery. Plenty of people hold themselves to strict rules about alcohol or gambling. People have occasional treats. |
| 440 | Hands wash hands; give that you may get [Epicharmus] |
| Full Idea: The hand washes the hand; give something and you may get something. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B30), quoted by (who?) - where? |
| 4580 | All virtues benefit either the public, or the individual who possesses them [Hume] |
| Full Idea: I desire you to consider if there be any quality that is virtuous, without having a tendency either to the public good or to the good of the person who possesses it. | |
| From: David Hume (Letters [1739], to Hutcheson 1739) | |
| A reaction: Obviously this is generally true. How, though, does it benefit the individual to secretly preserve their integrity? I go round to visit a friend to repay a debt; I am told they have died; I quietly leave some money on the table and leave. Why? |
| 441 | Against a villain, villainy is not a useless weapon [Epicharmus] |
| Full Idea: Against a villain, villainy is not a useless weapon. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B32), quoted by (who?) - where? |
| 4579 | The idea of a final cause is very uncertain and unphilosophical [Hume] |
| Full Idea: Your sense of 'natural' is founded on final causes, which is a consideration that appears to me pretty uncertain and unphilosophical. | |
| From: David Hume (Letters [1739], to Hutcheson 1739) | |
| A reaction: This is the rejection of Aristotelian teleology by modern science. I agree that the notion of utterly ultimate final cause is worse than 'uncertain' - it is an impossible concept. Nevertheless, I prefer Aristotle to Hume. Nature can teach us lessons. |
| 20705 | That events could be uncaused is absurd; I only say intuition and demonstration don't show this [Hume] |
| Full Idea: I never asserted so absurd a proposition as that anything might arise without a cause: I only maintained that our certainty of the falsehood of that proposition proceeded neither from intuition nor from demonstration, but from another source. | |
| From: David Hume (Letters [1739], 1754), quoted by Brian Davies - Introduction to the Philosophy of Religion 5 'God' | |
| A reaction: Since the other source is habit, he is being a bit disingenuous. While rational intuition and demonstration give a fairly secure basis for the universality of causation, mere human habits of expectation give very feeble grounds. |
| 439 | God knows everything, and nothing is impossible for him [Epicharmus] |
| Full Idea: Nothing escapes the divine, this you must realise. God himself is our overseer, and nothing is impossible for him. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B23), quoted by (who?) - where? |
| 443 | Human logos is an aspect of divine logos, and is sufficient for successful living [Epicharmus] |
| Full Idea: Man has calculation, but there is also the divine logos. But human logos is sprung from the divine logos, and it brings to each man his means of life, and his maintenance. | |
| From: Epicharmus (comedies (frags) [c.470 BCE], B57), quoted by (who?) - where? |