display all the ideas for this combination of texts
9 ideas
4187 | 'There is nothing without a reason why it should be rather than not be' (a generalisation of 'Why?') [Schopenhauer] |
Full Idea: The Principle may be stated as 'There is nothing without a reason why it should be rather than not be', which is a generalisation of the assumption which justifies the question 'Why?', which is the mother of all science. | |
From: Arthur Schopenhauer (Abstract of 'The Fourfold Root' [1813], Ch.I) | |
A reaction: This faith is the core of philosophy, to be maintained against all defeatists like Wittgenstein and Colin McGinn. Reality must be rational, or we wouldn't be here to think about it. (Maybe!) |
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 |
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). |
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 |
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) |
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 |
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. |