display all the ideas for this combination of texts
8 ideas
| 1601 | The most certain basic principle is that contradictories can't be true at the same time [Aristotle] |
| Full Idea: The most certain of all basic principles is that contradictory propositions are not true at the same time. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1011b13) | |
| A reaction: Principle of Noncontradiction |
| 11282 | Aristotle does not take the principle of non-contradiction for granted [Aristotle, by Politis] |
| Full Idea: Aristotle goes to great lengths to defend the principle of non-contradiction, and does not at all think that it is obviously true. | |
| From: report of Aristotle (Metaphysics [c.324 BCE], logic) by Vassilis Politis - Aristotle and the Metaphysics 5.1 |
| 6561 | A thing cannot be both in and not-in the same thing (at a given time) [Aristotle] |
| Full Idea: It is impossible for the same thing at the same time both to be-in and not to be-in the same thing in the same respect. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1005b19) | |
| A reaction: Aristotle is really discussing non-contradiction here, but this formulation is very close to Leibniz's Law (that two identical things must have identical properties). |
| 11281 | We cannot say that one thing both is and is not a man [Aristotle] |
| Full Idea: It is not possible to say truly at the same time that the same thing both is and is not a man. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1006b33) |
| 1602 | For Aristotle predication is regulated by Non-Contradiction, because underlying stability is essential [Roochnik on Aristotle] |
| Full Idea: The Principle of Noncontradiction is for Aristotle the ultimate regulator of predication. In order for any predication to be significant it must refer to something definite and stable. | |
| From: comment on Aristotle (Metaphysics [c.324 BCE], 1011b13) by David Roochnik - The Tragedy of Reason p.152 |
| 608 | There is no middle ground in contradiction, but there is in contrariety [Aristotle] |
| Full Idea: With contradiction there can be no intermediate state, whereas with contrariety there can be. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1055b02) |
| 627 | If everything is made of opposites, are the opposed things made of opposites? [Aristotle] |
| Full Idea: If all things are composed of opposites, how can the things of which the opposites are made be composed of opposites? | |
| From: Aristotle (Metaphysics [c.324 BCE], 1075a23) | |
| A reaction: A nice warning against being too simplistic in metaphysics. |
| 628 | Not everything is composed of opposites; what, for example, is the opposite of matter? [Aristotle] |
| Full Idea: All things are not composed of opposites, because matter is not the opposite of anything. | |
| From: Aristotle (Metaphysics [c.324 BCE], 1075a28) | |
| A reaction: A nice counterexample |