The Salesman has an advantage here which he often overlooks. We refer to the fact that the very objections of the prospect, and his questions give a key to his mental operations, which may be followed up by the Salesman. He knows now what is on the prospect's mind, and what are his general feelings, views, and inclinations regarding the matter. When he begins to talk he gives you a glimpse at his motives, prejudices, hopes and fears. It is quite an art to lead the prospect to ask the questions or to make the objections to which you have a strong answering argument. You then are able to turn back upon him his own argument. _It is a psychological fact that the force of a statement made in answer to an interrogative objection, is much stronger than would be the same statement made without the question or objection._ Macbain says: "Lincoln, it is related, early learned in beginning the study of law, that he did not know what it was to prove a thing. By means of careful, conscientious study, in which he took up the problems of Euclid, one by one, he satisfied himself that he then realized absolutely what it meant to prove a proposition. One of the most eminent judges of the Iowa judiciary regards every legal problem as a proposition to be proved by a chain of reasoning. The salesman who determines with absolute accuracy what it means, first, to prove a proposition, and second to apply the general principles of demonstration to an immediate matter in hand, knows just how far to go in making his demonstration, what to include and what to exclude. He can see in his mind's eye the chain of evidence that he is fashioning and will make that fabric of his mind exact, logical and convincing." (Note:--In order to train the student in logical thinking, development of the logical faculties, and the art of expressing one's thoughts in a logical and effective manner, we would suggest that he make inquiry regarding the volumes of the present series known as "The Art of Logical Thinking, or The Laws of Reasoning;" "Thought-Culture, or Practical Mental Training;" and "The Art of Expression." These books are published by the house issuing the present volume.)