'When you say ''hill'', 'the Queen interrupted, 'I could show you hills, in comparison with which you'd call that a valley.' 'No, I shouldn't,' said Alice, surprised into contradicting her at last: 'a hill can't be a valley, you know. That would be nonsense.' The Red Queen shook her head.'You may call it ''nonsense'' if you like,' she said,'but I've heard nonsense, compared with which that would be as sensible as a dictionary!'
The principles of logic and mathematics are true simply because we never allow them to be anything else. And the reason for this is that we cannot abandon them without contradicting ourselves, without sinning against the rules which govern the use of language, and so making our utterances self-stultifying. In other words, the truths of logic and mathematics are analytic propositions or tautologies.alfred jules ayer
I write plays because dialogue is the most respectable way of contradicting myself.tom stoppard
Saussure ... winds up contradicting the most interesting critical motive of the Course, making of linguistics the regulatory model, the "pattern" for a general semiology of which it was to be, by all rights and theoretically, only a part. The theme of the arbitrary, thus, is turned away from its most fruitful paths (formalization) toward a hierarchizing teleology... One finds exactly the same gesture and the same concepts in Hegel .jacques derrida
Our alleged facts might be true in all kinds of ways without contradicting any truth already known. I will dwell now on only one possible line of explanation, not that I see any way of elucidating all the new phenomena I regard as genuine, but because it seems probable I may shed a light on some of those phenomena. All the phenomena of the universe are presumably in some way continuous; and certain facts, plucked as it were from the very heart of nature , are likely to be of use in our gradual discovery of facts which lie deeper still.william crookes