‘But it is one of the fundamental prejudices of logic as hitherto understood and of ordinary thinking, that contradiction is not so characteristically essential and immanent a determination as identity; but in fact, if it were a question of grading the two determinations and they had to be kept separate, then contradiction would have to be taken as the profounder determination and more characteristic of essence. For as against contradiction, identity is merely the determination of the simple immediate, of dead being; but contradiction is the root of all movement and vitality; it is only in so far as something has a contradiction within it that it moves, has an urge and activity.’
G.W.F.Hegel, Hegel’s Science of Logic, (Vol. I The Objective Logic) Trans., A.V.Miller, Humanities Press, New York, 1976, 439
materialism, mysticism and art 
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