5 ideas
| 13007 | Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz] |
| Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points. | |
| From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13 | |
| A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry. |
| 16045 | General facts supervene on particular facts, but cannot be inferred from them [Russell, by Bennett,K] |
| Full Idea: Russell noted that you cannot arrive at general facts by inference from numerous particular facts, ..but general facts logically supervene on particular ones. So the general facts supervene, but are not entailed. | |
| From: report of Bertrand Russell (On Relations of Universals and Particulars [1911]) by Karen Bennett - Supervenience §3.2 | |
| A reaction: The belief that the general facts supervene on the particular ones then seems to be more a matter of faith than of fact. Or maybe it is analytic, depending on what we understand by 'general'. Universal, or generalised? |
| 14327 | Trope theorists cannot explain how tropes resemble each other [Russell, by Mumford] |
| Full Idea: The trope theorist cannot explain how a number of tropes resemble each other. | |
| From: report of Bertrand Russell (On Relations of Universals and Particulars [1911]) by Stephen Mumford - Dispositions 07.6 | |
| A reaction: [My 13,000th Idea: 31/10/11] Every theory is left with something it cannot explain. Is it likely that we could come up with an explanation of resemblance? It seems like a combination of identity in the physics, and identity in the brain mechanisms. |
| 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. |
| 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. |