The rhetorician and the dialectician distinguished

“The business of the rhetorician is to plant and establish some given point of persuasion, whether as to a general resolution or a particular fact, in the bosoms of certain auditors before him: hence he gives prominence and emphasis to some views of the question, suppressing or discrediting others, and especially keeping out of sight all the difficulties surrounding the conclusion at which he is aiming. On the other hand, the business of the dialectician is, not to establish any foreknown conclusion, but to find out which among all supposable conclusions are untenable, and which is the most tenable or best. Hence all the difficulties attending every one of them must be brought fully into view and discussed: until this has been done, the process is not terminated, nor can we tell whether any assured conclusion is attainable or not.” (George Grote, Plato, and the Other Companions of Socrates)