8 ideas
| 3340 | Von Neumann defines each number as the set of all smaller numbers [Neumann, by Blackburn] |
| Full Idea: Von Neumann defines each number as the set of all smaller numbers. | |
| From: report of John von Neumann (works [1935]) by Simon Blackburn - Oxford Dictionary of Philosophy p.280 |
| 3355 | Von Neumann wanted mathematical functions to replace sets [Neumann, by Benardete,JA] |
| Full Idea: Von Neumann suggested that functions be pressed into service to replace sets. | |
| From: report of John von Neumann (works [1935]) by José A. Benardete - Metaphysics: the logical approach Ch.23 |
| 22716 | Von Neumann defined ordinals as the set of all smaller ordinals [Neumann, by Poundstone] |
| Full Idea: At age twenty, Von Neumann devised the formal definition of ordinal numbers that is used today: an ordinal number is the set of all smaller ordinal numbers. | |
| From: report of John von Neumann (works [1935]) by William Poundstone - Prisoner's Dilemma 02 'Sturm' | |
| A reaction: I take this to be an example of an impredicative definition (not predicating something new), because it uses 'ordinal number' in the definition of ordinal number. I'm guessing the null set gets us started. |
| 8872 | It is widely supposed that externalism cannot be reconciled with first-person authority [Davidson] |
| Full Idea: It has been widely supposed that externalism, which holds that the contents of a person's propositional attitudes are partly determined by factors of which the person may be ignorant, cannot be reconciled with first-person authority. | |
| From: Donald Davidson (Epistemology Externalized [1990], p.197) | |
| A reaction: It is certainly a bit puzzling if you go around saying 'Actually, people don't know their own thoughts'. Davidson aims to defend first-person authority. The full story is developed in Tyler Burge's views on 'anti-individualism'. |
| 8874 | It is hard to interpret a speaker's actions if we take a broad view of the content [Davidson] |
| Full Idea: It will explain a speaker's actions far better if we interpret him as he intended to be interpreted, than if we suppose he means and thinks what someone else might mean and think who used the same words 'correctly'. | |
| From: Donald Davidson (Epistemology Externalized [1990], p.199) | |
| A reaction: This comes down to the fact that our actions have to be motivated by internal meanings. If I defer to experts on the essence of gold, I still buy gold according to how I myself understand it. So meaning has two components? |
| 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. |
| 8873 | The cause of a usage determines meaning, but why is the microstructure of water relevant? [Davidson] |
| Full Idea: While I agree that the usual cause of the use of the word determines what it means, I do not see why sameness of microstructure is necessarily the relevant similarity that determines my reference of the word 'water'. | |
| From: Donald Davidson (Epistemology Externalized [1990], p.198) | |
| A reaction: This is a problem for essentialists who build their views on semantic considerations. But the stability of what causes 'water' thoughts is the microstructure of water. However, that is an explantion of meaning, not a definition of it. |
| 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. |