Secondly, we have several instances of habits which may be revived by one single word; as when a person who has, by rote, any periods of a discourse, or any number of verses, will be put in remembrance of the whole, which he is at a loss to recollect, by that single word or expression with which they begin. Thirdly, I believe every one who examines the situation of his mind in reasoning, will agree with me, that we do not annex distinct and complete ideas to every term we make use of, and that in talking of _government, church, negociation, conquest_, we seldom spread out in our minds all the simple ideas of which these complex ones are composed. 'Tis however observable, that notwithstanding this imperfection, we may avoid talking nonsense on these subjects, and may perceive any repugnance among the ideas as well as if we had a full comprehension of them. Thus, if instead of saying, _that in war the weaker have always recourse to negociation_, we should say, _that they have always recourse to conquest_, the custom which we have acquired of attributing certain relations to ideas, still follows the words, and makes us immediately perceive the absurdity of that proposition; in the same manner as one particular idea may serve us in reasoning concerning other ideas, however different from it in several circumstances. Fourthly, as the individuals are collected together, and placed under a general term with a view to that resemblance which they bear to each other, this relation must facilitate their entrance in the imagination, and make them be suggested more readily upon occasion. And, indeed, if we consider the common progress of the thought, either in reflection or conversation, we shall find great reason to be satisfied in this particular. Nothing is more admirable than the readiness with which the imagination suggests its ideas, and presents them at the very instant in which they become necessary or useful. The fancy runs from one end of the universe to the other, in collecting those ideas which belong to any subject. One would think the whole intellectual world of ideas was at once subjected to our view, and that we did nothing but pick out such as were most proper for our purpose. There may not, however, be any present, beside those very ideas, that are thus collected by a kind of magical faculty in the soul, which, though it be always most perfect in the greatest geniuses, and is properly what we call a genius, is however inexplicable by the utmost efforts of human understanding.