What is the Antonym of Logic?
Logic is a noun - meaning 'the science of reasoning' the origin can be dated back to the ancient Greek 'logike'
Logic was studied in several ancient civilizations, including India, China, Persia and Greece. In the West, logic was established as a formal discipline by Aristotle - Greek philosipher and scientist born in Stagirus, northern Greece in 384 BCE (Before Christian Era)
Although it may be debated there is no true Antonym (a word opposite in meaning to another) for Logic the word 'Unreasonableness' could be considered an Antonym, as well as 'Illogicality' or 'Irrationality'.
If you'd like to find Antonyms, Synonyms and Definitons of every word in the Dictionary - http://thesaurus.com/ - is a great resource.
If you'd like to find rhymes for words - www.rhymezone.com/ - is a very useful resource that displays rhymes for every word in the dictionary, grouping the rhymes into one syllable, two syllable and so forth and also displaying near rhymes.
For more information regarding Greek Philosophy please check out this video with an introduction into the subject: