6 ideas
| 16706 | Generation is when local motions aggregate to become a single subject [Nicholas of Autrecourt] |
| Full Idea: In the case of natural things there is only local motion. When from such motion there follows an aggregation of natural bodies that are gathered to one another and acquire the nature of a single subject, this is called generation. | |
| From: Nicholas of Autrecourt (Tractatus [1335], Ch. 1) | |
| A reaction: This is explosive atomistic corpuscularianism, three centuries before its appointed date. He was duly suppressed. Can he give an account of the 'nature of a single subject' in this way? |
| 13768 | Validity can preserve certainty in mathematics, but conditionals about contingents are another matter [Edgington] |
| Full Idea: If your interest in logic is confined to applications to mathematics or other a priori matters, it is fine for validity to preserve certainty, ..but if you use conditionals when arguing about contingent matters, then great caution will be required. | |
| From: Dorothy Edgington (Conditionals [2001], 17.2.1) |
| 13770 | There are many different conditional mental states, and different conditional speech acts [Edgington] |
| Full Idea: As well as conditional beliefs, there are conditional desires, hopes, fears etc. As well as conditional statements, there are conditional commands, questions, offers, promises, bets etc. | |
| From: Dorothy Edgington (Conditionals [2001], 17.3.4) |
| 13764 | Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? [Edgington] |
| Full Idea: Are conditionals truth-functional - do the truth values of A and B determine the truth value of 'If A, B'? Are they non-truth-functional, like 'because' or 'before'? Do the values of A and B, in some cases, leave open the value of 'If A,B'? | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: I would say they are not truth-functional, because the 'if' asserts some further dependency relation that goes beyond the truth or falsity of A and B. Logical ifs, causal ifs, psychological ifs... The material conditional ⊃ is truth-functional. |
| 13765 | 'If A,B' must entail ¬(A & ¬B); otherwise we could have A true, B false, and If A,B true, invalidating modus ponens [Edgington] |
| Full Idea: If it were possible to have A true, B false, and If A,B true, it would be unsafe to infer B from A and If A,B: modus ponens would thus be invalid. Hence 'If A,B' must entail ¬(A & ¬B). | |
| From: Dorothy Edgington (Conditionals [2001], 17.1) | |
| A reaction: This is a firm defence of part of the truth-functional view of conditionals, and seems unassailable. The other parts of the truth table are open to question, though, if A is false, or they are both true. |
| 20523 | Property is theft! [Proudhon] |
| Full Idea: Property is theft! | |
| From: Pierre-Joseph Proudhon (What is Property? [1840]), quoted by Jonathan Wolff - An Introduction to Political Philosophy (Rev) | |
| A reaction: [Context in Proudhon's book?] This may not be the essence of property rights today, but it is almost undeniable as a historical fact. William the Conqueror kills the opposition in battle, and then gives English land to his friends. |