3 ideas
3299 | In logic identity involves reflexivity (x=x), symmetry (if x=y, then y=x) and transitivity (if x=y and y=z, then x=z) [Baillie] |
Full Idea: In logic identity is an equivalence relation, which involves reflexivity (x=x), symmetry (if x=y, then y=x), and transitivity (if x=y and y=z, then x=z). | |
From: James Baillie (Problems in Personal Identity [1993], Intr p.4) |
6368 | If my ticket won't win the lottery (and it won't), no other tickets will either [Kyburg, by Pollock/Cruz] |
Full Idea: The Lottery Paradox says you should rationally conclude that your ticket will not win the lottery, and then apply the same reasoning to all the other tickets, and conclude that no ticket will win the lottery. | |
From: report of Henry E. Kyburg Jr (Probability and Logic of Rational Belief [1961]) by J Pollock / J Cruz - Contemporary theories of Knowledge (2nd) §7.2.8 | |
A reaction: (Very compressed by me). I doubt whether this is a very deep paradox; the conclusion that I will not win is a rational assessment of likelihood, but it is not the result of strict logic. |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us. | |
From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus | |
A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts? |