5 ideas
19404 | Necessities rest on contradiction, and contingencies on sufficient reason [Leibniz] |
Full Idea: The principle of contradiction is the principle of necessity, and the principle that a sufficient reason must be given is the principle of contingency. | |
From: Gottfried Leibniz (On Sufficient Reason [1686], p.95) | |
A reaction: [this paragraph is actually undated] Contradictions occur in concrete actuality, as well as in theories and formal systems. If so, then there are necessities in nature. Are they discoverable a posteriori? Leibniz says not. |
19423 | By an 'idea' I mean not an actual thought, but the resources we can draw on to think [Leibniz] |
Full Idea: What I mean by an idea is not a certain act of thinking, but a power or faculty such that we have an idea of a thing even if we are not thinking about it but know that we can think it when the occasion arises. | |
From: Gottfried Leibniz (What is an Idea? [1676], p.281) | |
A reaction: 'Idea' tends to be used in the seventeenth century to mean an actual mental event. It is because Leibniz believes in the unconscious mind that he can offer this rather different, and probably superior, notion of an 'idea'. |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
19403 | Each of the infinite possible worlds has its own laws, and the individuals contain those laws [Leibniz] |
Full Idea: As there are an infinity of possible worlds, there are also an infinity of laws, some proper to one, another to another, and each possible individual of any world contains in its own notion the laws of its world. | |
From: Gottfried Leibniz (On Sufficient Reason [1686], p.95) | |
A reaction: Hence Leibniz is not really a scientific essentialist, in that he doesn't think the laws arise out of the nature of the matter consituting the world. I wonder if the primitive matter of bodies which attaches to the monads is the same in each world? |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |