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2. Reason / B. Laws of Thought / 3. Non-Contradiction

[a proposition is claimed to be both true and false]

18 ideas
Contradiction is impossible [Antisthenes (I) ,by Aristotle]
A thing cannot be both in and not-in the same thing (at a given time) [Aristotle]
We cannot say that one thing both is and is not a man [Aristotle]
The most certain basic principle is that contradictories can't be true at the same time [Aristotle]
For Aristotle predication is regulated by Non-Contradiction, because underlying stability is essential [Roochnik on Aristotle]
Aristotle does not take the principle of non-contradiction for granted [Aristotle ,by Politis]
From an impossibility anything follows [William of Ockham]
If truth is just non-contradiction, we must take care that our basic concepts aren't contradictory [Hegel]
Self-contradiction doesn't reveal impossibility; it is inductive impossibility which reveals self-contradiction [Peirce]
Our inability to both affirm and deny a single thing is merely an inability, not a 'necessity' [Nietzsche]
Non-contradiction was learned from instances, and then found to be indubitable [Russell]
The problem is to explain the role of contradiction in social life [Wittgenstein]
If you say that a contradiction is true, you change the meaning of 'not', and so change the subject [Quine]
To affirm 'p and not-p' is to have mislearned 'and' or 'not' [Quine]
Someone standing in a doorway seems to be both in and not-in the room [Priest,G ,by Sorensen]
You cannot rationally deny the principle of non-contradiction, because all reasoning requires it [Baggini /Fosl]
The law of noncontradiction makes the distinction between asserting something and denying it [Fogelin]
Non-contradiction is unjustified, so it only reveals a fact about thinking, not about reality? [Meillassoux]