11 ideas
| 3067 | A philosopher should have principles ready for understanding, like a surgeon with instruments [Aurelius] |
| Full Idea: As physicians have always their instruments and knives ready for cases which suddenly require their skill, so should you have principles ready for the understanding of things divine and human. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 3.13) | |
| A reaction: Nice. Philosophy is the training ground where wisdom and good living are made possible, but it cannot be a substitute for living. |
| 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. |
| 18091 | Infinitesimals are ghosts of departed quantities [Berkeley] |
| Full Idea: The infinitesimals are the ghosts of departed quantities. | |
| From: George Berkeley (The Analyst [1734]), quoted by David Bostock - Philosophy of Mathematics 4.3 | |
| A reaction: [A famous phrase, but as yet no context for it] |
| 3072 | Everything is changing, including yourself and the whole universe [Aurelius] |
| Full Idea: All things are changing; and you yourself are in continuous mutation and in a manner in continuous destruction, and the whole universe too. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 9.19) |
| 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). |
| 3066 | Nothing is evil which is according to nature [Aurelius] |
| Full Idea: Nothing is evil which is according to nature. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 2.17) | |
| A reaction: A bit hopeful. Sounds tautological. I.e. anything which is agreed to be evil is probably immediately labelled as 'unnatural'. What would he agree was evil? |
| 3071 | Justice has no virtue opposed to it, but pleasure has temperance opposed to it [Aurelius] |
| Full Idea: In the constitution of the rational animal I see no virtue which is opposed to justice; but I see a virtue which is opposed to pleasure, and that is temperance. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 8.39) | |
| A reaction: There are plenty of hideous things opposed to justice, but presumably that immediately disqualifies them from being virtues. |
| 3069 | The art of life is more like the wrestler's than the dancer's [Aurelius] |
| Full Idea: The art of life is more like the wrestler's than the dancer's. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 7.61) |
| 3065 | Humans are naturally made for co-operation [Aurelius] |
| Full Idea: We are made for cooperation, like feet, like hands, like eyelids, like the rows of upper and lower teeth. To act against one another, then, is contrary to nature. | |
| From: Marcus Aurelius (The Meditations (To Himself) [c.170], 2.1) |