It quickly radiated through every department of history. "In every singing age," he said, "a single saeculum is almost like a single man. It is all one mind, one soul."* This conception involved a new social law, and radically altered the current opinions concerning the relation of individual effort to the larger forces that affect the development of nations. The creative energy of remarkable minds was not, indeed, lessened in importance, but spontaneity, in this connection, acquired a new meaning; and for the _Deus ex machina_ of the olden time was substituted the cumulative force of centuries of progressive advancement, culminating, it is true, at last in the triumphant synthesis of genius. The commotion which the Wolfian theory has stirred up in the literary world is largely due to the wide range of ideas which it affected. Yet it was itself but a part of that general movement which, toward the close of the last century, became conspicuous in its effects on every field of human inquiry. Everywhere the shackles of authority were thrown off, and, in place of blindly accepting the testimony of the past, men turned to investigate for themselves. A new principle of research was everywhere acknowledged, a new method was created, and science, natural and historical, entered upon that astonishing career of discovery whose rich promise for the future we have but begun to anticipate.** * In a letter given in Kttrte's "Leben und Studien F. A Wolf s." i., p. 307. ** Scientific pursuits are distinguished from others, not by the material, but by the method of knowledge. The mere collection of data, however multiplied in detail, however abstruse the subjects to which they may refer, does not of itself deserve the name of science. The term properly applies only when phenomena are placed in causal relation, and the laws which govern their development are traced. Measured by this standard, every attempt to explain the growth of human thought and institutions, and to elucidate the laws which have acted in the process of their evolution, has a just claim to be classed under the head of scientific inquiry.