mains, which also occurs in rhetorical arguments, and in almost all the other arts. For they who discovered principles, altogether made but little progress; but men who are now celebrated, receiving, as it were, by succession from many who promoted (art) by parts, have thus increased it; Tisias after the tirst (authors), but Thrasymachus after Tisias, Theodorus after him, and many (others) have brought together many particulars, wherefore it is no wonder that the art has a certain multitude (of precepts). Of this subject, however, there has not been a part cultivated, and a part not before, but nothing of it has existed at all, for of those who employed themselves about contentious arguments for gain, there was a certain instruction, similar to the treatise of Gorgias. For some gave rhetorical, others interrogative discourses to learn, into which each thought their conversation with each other would most often fall. Hence the instruction indeed to their disciples was rapid, but without art, since they supposed they should instruct them by delivering not art, but the effects of art, just as if a person professing to deliver the science of keeping feet from injury, should afterwards not teach shoemaking, nor whence such things (as safe-guards for the feet) may be procured, but should exhibit many kinds of shoes of every form; for he would indeed afford assistance as to use, yet not discover the art. And indeed, about rhetoric, many old discourses are extant, but about the art of syllogism we have received nothing at all from the ancients, but we have laboured for a long time by the exercise of investigation. If then, it appear to you, when you have inspected (our writings), that this method derived from such materials as existed originally, when compared with other treatises which have been increased from tradition, has been (handled) sufficiently, it remains for you all,
