I, therefore, advise that our finished Orator make himself master of every thing in the art of Logic, which is applicable to his profession:--an art (as your thorough knowledge of it has already informed you) which is taught after two methods. For Aristotle himself has delivered a variety of precepts concerning the art of Reasoning:--and besides these, the _Dialecticians_ (as they are called) have produced many intricate and thorny speculations of their own. I am, therefore, of opinion, that he who is ambitious to be applauded for his Eloquence, should not be wholly unacquainted with this branch of Erudition; but that he ought (at least) to be properly instructed either in the old method, or in that of _Chrysippus_. In the first place, he should understand the force, the extension, and the different species of words as they stand singly, or connected into sentences. He should likewise be acquainted with the various modes and forms in which any conception of the mind may be expressed--the methods of distinguishing a true proposition from a false one;--the different conclusions which result from different premises;--the true consequences and opposites to any given proposition;--and, if an argument is embarrassed by ambiguities, how to unravel each of them by an accurate distinction. These particulars, I say, should be well understood by an Orator, because they are such as frequently occur: but as they are naturally rugged and unpleasing, they should be relieved in practice by an easy brilliance of expression. But as in every topic which is discussed by reason and method, we should first settle what it is we are to discourse upon,--(for unless the parties in a dispute are agreed about the subject of it, they can neither reason with propriety, nor bring the argument to an issue;)--it will frequently be necessary to explain our notions of it, and, when the matter is intricate, to lay it open by a _definition_;--for a _definition_ is only a sentence, or explanation, which specifies, in as few words as possible, the nature of the object we propose to consider. After the _genus_, or kind, has been sufficiently determined, we must then proceed (you know) to examine into it's different species, or subordinate parts, that our whole discourse may be properly distributed among them. Our Orator, then, should be qualified to make a just definition;--though not in such a close and contracted form, as in the critical debates of the Academy, but more explicitly and copiously, and as will be best adapted to the common way of thinking, and the capacity of the vulgar. He is likewise, as often as occasion requires, to divide the genus into it's proper species, so as to be neither defective, nor redundant. But _how_ and _when_ this should be done, is not our present business to consider: because, as I observed before, I am not to assume the part of a teacher, but only of a critic and a judge.