Sophist

n.	1.	One of a class of men who taught eloquence, philosophy, and politics in ancient Greece; especially, one of those who, by their fallacious but plausible reasoning, puzzled inquirers after truth, weakened the faith of the people, and drew upon themselves general hatred and contempt. Many of the Sophists doubdtless card not for truth or morality, and merely professed to teach how to make the worse appear the better reason; but there scems no reason to hold that they were a special class, teaching special opinions; even Socrates and Plato were sometimes styled Sophists. - Liddell & Scott.
	2.	Hence, an impostor in argument; a captious or fallacious reasoner.

Noun	1.	Sophist - any of a group of Greek philosophers and teachers in the 5th century BC who speculated on a wide range of subjects
	2.	sophist - someone whose reasoning is subtle and often specious Synonyms: casuist

Jesuit, casuist, choplogic, cosmologist, dialectician, logicaster, logician, logistician, metaphysician, paralogist, philosophaster, philosophe, philosopher, philosophizer, ratiocinator, rationalist, rationalizer, reasoner, sophister, speculator, syllogist, syllogizer, thinker