But be our conceptions adequate or inadequate, and be our stock of them large or small, they are all we have to work with. If an educated man is, as I said, a group of organized tendencies to conduct, what prompts the conduct is in every case the man's conception of the way in which to name and classify the actual emergency. The more adequate the stock of ideas, the more 'able' is the man, the more uniformly appropriate is his behavior likely to be. When later we take up the subject of the will, we shall see that the essential preliminary to every decision is the finding of the right _names_ under which to class the proposed alternatives of conduct. He who has few names is in so far forth an incompetent deliberator. The names--and each name stands for a conception or idea--are our instruments for handling our problems and solving our dilemmas. Now, when we think of this, we are too apt to forget an important fact, which is that in most human beings the stock of names and concepts is mostly acquired during the years of adolescence and the earliest years of adult life. I probably shocked you a moment ago by saying that most men begin to be old fogies at the age of twenty-five. It is true that a grown-up adult keeps gaining well into middle age a great knowledge of details, and a great acquaintance with individual cases connected with his profession or business life. In this sense, his conceptions increase during a very long period; for his knowledge grows more extensive and minute. But the larger categories of conception, the sorts of thing, and wider classes of relation between things, of which we take cognizance, are all got into the mind at a comparatively youthful date. Few men ever do acquaint themselves with the principles of a new science after even twenty-five. If you do not study political economy in college, it is a thousand to one that its main conceptions will remain unknown to you through life. Similarly with biology, similarly with electricity. What percentage of persons now fifty years old have any definite conception whatever of a dynamo, or how the trolley-cars are made to run? Surely, a small fraction of one per cent. But the boys in colleges are all acquiring these conceptions.