              In its third guise, dialectic has a role to play in ‘science conducted in a philosophical manner’ (pros tas kata philosphian epistêmas; Top. 101a27–28, 101a34), where this sort of science includes what we actually find him pursuing in his major philosophical treatises. In these contexts, dialectic helps to sort the endoxa, relegating some to a disputed status while elevating others; it submits endoxa to cross-examination in order to test their staying power; and, most notably, according to Aristotle, dialectic puts us on the road to first principles (Top. 100a18–b4). If that is so, then dialectic plays a significant role in the order of philosophical discovery: we come to establish first principles in part by determining which among our initial endoxa withstand sustained scrutiny. Here, as elsewhere in his philosophy, Aristotle evinces a noteworthy confidence in the powers of human reason and investigation.