7 ideas
| 7791 | The simplest of the logics based on possible worlds is Lewis's S5 [Lewis,CI, by Girle] |
| Full Idea: C.I.Lewis constructed five axiomatic systems of modal logic, and named them S1 to S5. It turns out that the simplest of the logics based on possible worlds is the same as Lewis's S5. | |
| From: report of C.I. Lewis (works [1935]) by Rod Girle - Modal Logics and Philosophy 2.1 | |
| A reaction: Nathan Salmon ('Reference and Essence' 2nd ed) claims (on p.xvii) that "the correct modal logic is weaker than S5 and weaker even than S4". Which is the greater virtue, simplicity or weakness? |
| 11002 | Equating necessity with informal provability is the S4 conception of necessity [Lewis,CI, by Read] |
| Full Idea: C.I.Lewis's S4 system develops a sense of necessity as 'provability' in some fairly informal sense. | |
| From: report of C.I. Lewis (works [1935]) by Stephen Read - Thinking About Logic Ch. 4 |
| 12732 | Some necessary truths are brute, and others derive from final causes [Leibniz] |
| Full Idea: There is a difference between truths whose necessity is brute and geometric and those truths which have their source in fitness and final causes. | |
| From: Gottfried Leibniz (Letters to Remond de Montmort [1715], 1715.06.22/G III 645), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 6 | |
| A reaction: The second one is a necessity deriving from God's wisdom. Strictly it could have been otherwise, unlike 'geometrical' necessity, which is utterly fixed. |
| 19438 | Our large perceptions and appetites are made up tiny unconscious fragments [Leibniz] |
| Full Idea: Our great perceptions and our great appetites of which we are conscious, are composed of innumerable little perceptions and little inclinations of which we cannot be conscious. | |
| From: Gottfried Leibniz (Letters to Remond de Montmort [1715], 1715 §2) | |
| A reaction: I think this is a wonderfully accurate report of how the mind is, in comparison with the much more simplistic views presented by most philosophers of that era. And so much understanding flows from Leibniz's account. |
| 19415 | Passions reside in confused perceptions [Leibniz] |
| Full Idea: The passions of monads reside in their confused perceptions. | |
| From: Gottfried Leibniz (Letters to Remond de Montmort [1715], 1715) | |
| A reaction: He thinks perceptions come in degrees of confusion, all the way up to God, who alone has fully clear perceptions. He blames in on these confused perceptions. |
| 5845 | Niceratus learnt the whole of Homer by heart, as a guide to goodness [Xenophon] |
| Full Idea: Niceratus said that his father, because he was concerned to make him a good man, made him learn the whole works of Homer, and he could still repeat by heart the entire 'Iliad' and 'Odyssey'. | |
| From: Xenophon (Symposium [c.391 BCE], 3.5) | |
| A reaction: This clearly shows the status which Homer had in the teaching of morality in the time of Socrates, and it is precisely this acceptance of authority which he was challenging, in his attempts to analyse the true basis of virtue |
| 19439 | God produces possibilities, and thus ideas [Leibniz] |
| Full Idea: God is the source of possibilities and consequently of ideas. | |
| From: Gottfried Leibniz (Letters to Remond de Montmort [1715], 1715 §8) | |
| A reaction: A wonderfully individual conception of the nature of God. He produces the possibilities from which creation is chosen, and ideas and concepts are of everything which is non-contradictory, and thus possible. It all makes lovely sense! |