5 ideas
| 19389 | Truth is a characteristic of possible thoughts [Leibniz] |
| Full Idea: Truth really belongs to the class of thoughts which are possible. | |
| From: Gottfried Leibniz (Dialogue on Things and Words [1677], p.7) | |
| A reaction: I like the fact that this ties truth to 'thoughts', rather than peculiar abstract unthought entities called 'propositions', but I take it that thoughts which are possible but not thought will thereby not exist, so they can't be true. |
| 19388 | True and false seem to pertain to thoughts, yet unthought propositions seem to be true or false [Leibniz] |
| Full Idea: B: I concede that truth and falsity both pertain to thoughts and not to things. A: But this contradicts your previous opinion that a proposition remains true even when you are not thinking about it. | |
| From: Gottfried Leibniz (Dialogue on Things and Words [1677], p.7) | |
| A reaction: I don't trigger the truth of a proposition by thinking about it - I see that it is true. But I dislike the idea that reality is full of propositions, which seems to be mad metaphysics. So I deny unthought propositions are true, because there aren't any. |
| 1556 | By nature people are close to one another, but culture drives them apart [Hippias] |
| Full Idea: I regard you all as relatives - by nature, not by convention. By nature like is akin to like, but convention is a tyrant over humankind and often constrains people to act contrary to nature. | |
| From: Hippias (fragments/reports [c.430 BCE]), quoted by Plato - Protagoras 337c8 |
| 20646 | Helmholtz used 'energy' to mathematically link heat, light, electricity and magnetism [Helmholtz, by Watson] |
| Full Idea: Helmholtz provided the requisite mathematical formulation linking heat, light, electricity and magnetism, by treating these phenomena as different manifestations of 'energy'. | |
| From: report of Hermann von Helmholtz (On the Conservation of Force [1847]) by Peter Watson - Convergence 01 'Human' | |
| A reaction: I'm increasingly struck by the neglect by philosophers of nature of these amazing developments in 19th century physics, because they prefer the excitement of the latest nuclear physics. There is more philosophical interest in the earlier stages. |
| 20973 | All forces conserve the sum of kinetic and potential energy [Helmholtz, by Papineau] |
| Full Idea: Helmholtz crucially asserted that all forces conserve the sum of kinetic and potential energy; superficially non-conservative forces like friction are simply macroscopic manifestations of more fundamental forces conserving energy at the micro-level. | |
| From: report of Hermann von Helmholtz (On the Conservation of Force [1847]) by David Papineau - Thinking about Consciousness App 4.3 | |
| A reaction: Friction had been a problem case, because it appeared not to conserve energy when it slowed movement down. |