It has been remarked, my Hermippus, that though the ancient philosophers conveyed most of their instruction in the form of dialogue, this method of composition has been little practised in later ages, and has seldom succeeded in the hands of those who have attempted it. Accurate and regular argument, indeed, such as is now expected of philosophical inquirers, naturally throws a man into the methodical and didactic manner; where he can immediately, without preparation, explain the point at which he aims; and thence proceed, without interruption, to deduce the proofs on which it is established. To deliver a *SYSTEM in conversation, scarcely appears natural; and while the dialogue-writer desires, by departing from the direct style of composition, to give a freer air to his performance, and avoid the appearance of _Author_ and _Reader_, he is apt to run into a worse inconvenience, and convey the image of _Pedagogue_ and _Pupil_. Or, if he carries on the dispute in the natural spirit of good company, by throwing in a variety of topics, and preserving a proper balance among the speakers, he often loses so much time in preparations and transitions, that the reader will scarcely think himself compensated, by all the graces of dialogue, for the order, brevity and precision, which are sacrificed to them. There are some subjects, however, to which dialogue-writing is peculiarly adapted, and where it is still preferable to the direct and simple method of composition. Any point of doctrine, which is so _obvious_ that it scarcely admits of dispute, but at the same time so _important_ that it cannot be too often inculcated, seems to require some such method of handling it; where the novelty of the manner may compensate the triteness of the subject; where the vivacity of conversation may enforce the precept; and where the variety of lights, presented by various personages and characters, may appear neither tedious nor redundant. Any question of philosophy, on the other hand, which is so _obscure_ and _uncertain_, that human reason, can reach no fixed determination with regard to it; if it should be treated at all, seems to lead us naturally into the style of dialogue and conversation. Reasonable men may be allowed to differ, where no one can reasonably be positive: Opposite sentiments, even without any decision, afford an agreeable amusement; and if the subject be curious and interesting, the book carries us, in a manner, into company; and unites the two greatest and purest pleasures of human life, study and society.