4 ideas
3338 | Numbers have been defined in terms of 'successors' to the concept of 'zero' [Peano, by Blackburn] |
Full Idea: Dedekind and Peano define the number series as the series of successors to the number zero, according to five postulates. | |
From: report of Giuseppe Peano (works [1890]) by Simon Blackburn - Oxford Dictionary of Philosophy p.279 |
5897 | 0 is a non-successor number, all successors are numbers, successors can't duplicate, if P(n) and P(n+1) then P(all-n) [Peano, by Flew] |
Full Idea: 1) 0 is a number; 2) The successor of any number is a number; 3) No two numbers have the same successor; 4) 0 is not the successor of any number; 5) If P is true of 0, and if P is true of any number n and of its successor, P is true of every number. | |
From: report of Giuseppe Peano (works [1890]) by Antony Flew - Pan Dictionary of Philosophy 'Peano' | |
A reaction: Devised by Dedekind and proposed by Peano, these postulates were intended to avoid references to intuition in specifying the natural numbers. I wonder if they could define 'successor' without reference to 'number'. |
490 | Everything happens by reason and necessity [Leucippus] |
Full Idea: Nothing happens at random; everything happens out of reason and by necessity. | |
From: Leucippus (fragments/reports [c.435 BCE], B002), quoted by (who?) - where? |
1743 | The greatest deterrence for injustice is if uninjured parties feel as much indignation as those who are injured [Solon, by Diog. Laertius] |
Full Idea: Men can be most effectively deterred from committing injustice if those who are not injured feel as much indignation as those who are. | |
From: report of Solon (reports [c.600 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 01.So.10 |