late 14c., "objection, opposition; hostility, mutual opposition," also "absolute inconsistency," from Old French contradiction or directly from Late Latin contradictionem (nominative contradictio) "a reply, objection, counterargument," noun of action from past-participle stem of contradicere, in classical Latin contra dicere "to speak against, oppose in speech or opinion," from contra "against" (see contra) + dicere "to say, speak" (from PIE root *deik- "to show," also "pronounce solemnly"). Old English used wiðcwedennis as a loan-translation of Latin contradictio.
Meaning "an assertion of the direct opposite of what has been said or affirmed" is from c. 1400. Sense of "a contradictory fact or condition" is from 1610s. Contradiction in terms "self-contradictory phrase" is attested from 1705.
[C]ontradictions become elegance and propriety of language, for a thing may be excessively moderate, vastly little, monstrous pretty, wondrous common, prodigious natural, or devilish godly .... [Abraham Tucker, "The Light of Nature Pursued," 1805]