this kind, must be altogether avoided by dialecticians, viz. arguing against a name, unless any one should be otherwise incapable of discussing the proposition.
Notwithstanding, it is useful to discover differences, in order to (construct) syllogisms of the same, and of the different, and also to the knowledge of what each thing is. That it is useful for syllogisms about the same, and the different, is clear; for when we have discovered the difference of the things proposed, of whatever kind it may be, we shall have shown that they are not the same, (and it is useful) for the knowledge of what a thing is, because we are accustomed to separate the proper definition of the essence of each thing, by the peculiar differences of each.
On the other hand, speculation upon the similar, is useful for inductive reasons, and for hypothetical syllogisms, and for the statement of definitions. For inductive reasons then, because by the induction of similar particulars, we deem it proper to infer the universal, since it is not easy to form induction, when we are ignorant of similars. (It is useful also) for hypothetical syllogisms, because it is probable that as a thing subsists in one of those which are similar, so also it does in the rest, so that in order that we may discuss any of them sufficiently, we should previously acknowledge, that as a thing is in these, so also is its condition in the subject proposed; but when we have demonstrated that, we shall also have proved the proposition by hypothesis, for we have framed a demonstration, upon the supposition that as a thing is in these, so it is also, in the case of what is proposed. Again, for the statement of definitions (it is useful), since being able to comprehend what in each thing is identical, we shall not be in doubt as to what genus the thing proposed ought to be referred, in definition; for of those which are common, what is especially predicated in (the question) what a thing is, will be the genus; in like manner in those which are vastly different from each other, the contemplation of the similar is useful for definitions, as that tranquillity in the sea, is the same thing as serenity in the air, (for each of them is quiet,) and that a point in a line (is
