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.