But these two Propositions are Contradictories, so that one or other of them must be true.
"Symbolic Logic"
Lewis Carroll
Life in every form, nay, existence in any form, is a union of Contradictories, a complex of antagonisms; and the highest and deepest minds are those that are most adequate to have the vision of these antagonisms in their contrariety, and also in their unity; to see and hear as Empedocles did the eternal war and clamour, but to discern also, as he did in it and through it and behind it and about it, the eternal peace and the eternal silence.
"A Short History of Greek Philosophy"
John Marshall
It was in view of such perplexities as these that Aristotle set forth the true Contradictories of his four Modals.
"Logic, Inductive and Deductive"
William Minto