7 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. |
| 3597 | Foundations need not precede other beliefs [Wittgenstein] |
| Full Idea: I do not explicitly learn the propositions that stand fast for me. I can discover them subsequently like the axis around which a body rotates. | |
| From: Ludwig Wittgenstein (On Certainty [1951], §152), quoted by Michael Williams - Problems of Knowledge Ch.14 | |
| A reaction: A nice metaphor for the way in which axioms are derived. It is also close to Quine's metaphor of the 'net' of understanding, with the centre area 'standing fast'. Not neat and tidy, though. |
| 3596 | Total doubt can't even get started [Wittgenstein, by Williams,M] |
| Full Idea: Wittgenstein remarked that if you tried to doubt everything, you would not get as far as doubting anything. | |
| From: report of Ludwig Wittgenstein (On Certainty [1951]) by Michael Williams - Problems of Knowledge Ch.14 |
| 4721 | If you are not certain of any fact, you cannot be certain of the meaning of your words either [Wittgenstein] |
| Full Idea: If you are not certain of any fact, you cannot be certain of the meaning of your words either. | |
| From: Ludwig Wittgenstein (On Certainty [1951], §114) | |
| A reaction: A wonderfully challenging aphorism. I suspect that it is true, but not really a problem. We all know the meaning of 'Loch Ness Monster', as long as we don't get too fussy. And for local objects I am happy that I know the facts. |
| 6866 | It is disturbing if we become unreal when we die, but if time is unreal, then we remain real after death [Le Poidevin] |
| Full Idea: For the A-theorists called 'presentists' the past is as unreal as the future, and reality leaves us behind once we die, which is disturbing; but B-theorists, who see time as unreal, say we are just as real after our deaths as we were beforehand. | |
| From: Robin Le Poidevin (Interview with Baggini and Stangroom [2001], p.174) | |
| A reaction: See Idea 6865 for A and B theories. I wonder if this problem is only superficially 'disturbing'. Becoming unreal may sound more drastic than becoming dead, but they both sound pretty terminal to me. |
| 6867 | Existentialism focuses on freedom and self-making, and insertion into the world [Le Poidevin] |
| Full Idea: I take existentialism to be the focus on the freedom and self-making of the human being, and his or her insertion into the world. | |
| From: Robin Le Poidevin (Interview with Baggini and Stangroom [2001], p.222) | |
| A reaction: I take 'self-making' to be the key here. If neuroscientists somehow 'proved' that there was no free will, I don't see that making any difference to existentialism. 'Insertion' seems odd, unless it refers to growing up. |
| 6865 | A-theory says past, present, future and flow exist; B-theory says this just reports our perspective [Le Poidevin] |
| Full Idea: The A-theory regards our intuitive distinction of time into past, present and future as objective, and takes seriously the idea that time flows; the B-theory says this just reflects our perspective, like the spatial distinction between here and there. | |
| From: Robin Le Poidevin (Interview with Baggini and Stangroom [2001], p.174) | |
| A reaction: The distinction comes from McTaggart. Physics seems to be built on an objective view of time, and yet Einstein makes time relative. What possible evidence could decide between the two theories? |