Again, it is not in the history of man, as in natural history, where the structure of the various plants and animals forms by close analogy one connected system of species and genera; and where the growth, bloom, decay and extinction of individuals follow in an uniform order, like day and night, or like the change of the seasons. But in the sphere of human freedom; as man is a natural creature, but a natural creature endowed with free-will, that is to say, with the faculty of moral determination between the good or heavenly impulse, and the wicked or hostile principle; all these organic laws of nature form only the physical basis of his progress and history. And hardly do they form this—but rather a mere disposition of which the direction depends on man, or on the use he makes of his own freedom. It is only when that higher principle of man’s free-will has been weakened, debased, obscured, extinguished, and utterly confounded, that those laws of nature can hold good in history. Then indeed the symptoms of a diseased age, the organic vices of a nation, the prognostics of a general crisis of the world may be determined to a certain extent with the precision of medical science.
[Friedrich Schlegel, The Philosophy of History, James Burton Robertson, tr., Volume II, Lecture XV.]