conception of life, of the arts, philosophy, and literature at once set in. The authority of tradition was shaken, scientific truths began gradually to take the place of revealed truths, and civilization entered upon a new phase. To-day the old religious ideas have lost the greater part of their empire, and for that reason alone all the social institutions that rested upon them are threatened with dissolution.
Regarding ideas according to the importance of their working rather than to their worth, we may divide them into two classes. First are the great general directing and permanent ideas on which an entire civilization rests—the feudal and religious ideas of the middle ages, for example, and certain political conceptions of modern times; and, secondly, transient and changing ideas derived, to a certain extent perhaps, from the general ideas which arise and pass away in every age. Among these are the theories which guide art and literature at certain periods, such as those which have produced romanticism, naturalism, mysticism, etc. They are usually as superficial as the fashion, and change like it. They may be compared to the minor waves that are continually rising and vanishing on the surface of a river, while the fundamental ideas may be compared to the deep current that bears away the waters of the same river. Of the various transient ideas that arise in the course of ages, a few become in time fundamental directing ideas, but this is the result of rare combinations of special conditions.
It is as impossible to name the real creator of a great idea as to point out the author of a great invention. When an idea reaches the light and becomes capable of exercising influence, it is, like one of the great inventions, the sum of numerous anterior minor ideas. It has been subjected to long elaboration and numerous transformations. The originators of the idea are therefore far anterior to its propagators. The brains which conceived it live in regions inaccessible to the multitude. The results of their thought may exercise a considerable influence in the world, but they will not see it. If they were privileged to witness its development, they would not be likely to recognize the fruit of their meditations. From the intellectual heights whence the idea usually is derived, it comes down step by step, undergoing continual changes and modifications, till it takes on a shape accessible to the popular mind, when its triumph is assured. It then presents itself concentrated into a very small number of words, perhaps into only one, but that word evokes striking images, and consequently always impressive, whether they be seductive or terrible. Such were paradise and hell in the middle ages, short words that have the power of answering for everything, and to simple minds explaining everything. The word socialism repre-
