%4.  Retrospect.%

In order to avoid the appearance of arbitrary construction we have been sparing with references of a philosophico-historical character.  In conclusion, looking back at the period passed over, we may give expression to some convictions concerning the guiding threads in the development of modern philosophy, though these here claim only the rights of subjective opinion.

A mirror of modern culture, and conscious of its sharp antithesis to Scholasticism, modern philosophy in its pre-Kantian period is pre-eminently characterized by naturalism.  Nature, as a system of masses moved according to law, forms not only the favorite object of investigation, but also the standard by which psychical reality is judged and explained.  The two directions in which this naturalism expresses itself, the mechanical view of the world, which endeavors to understand the universe from the standpoint of nature and all becoming from the standpoint of motion,[1] and the intellectualistic view, which seeks to understand the mind from the standpoint of knowledge, are most intimately connected.  Where the general view of the All takes form and color from nature, a content and a mission can come to the mind from no other source than the external world; whether we (empirically) make it take up the material of representation from without or (rationalistically) make it create an ideal reproduction of the content of external reality from within, it is always the function of knowledge, conceived as the reproduction of a completed reality, which, since it brings us into contact with nature, advances into the foreground and determines the nature of psychical activity.  As is conceivable, along with dogmatic faith in the power of the reason to possess itself of the reality before it and to reconstrue it in the system of science, and with triumphant references to the mathematical method as a guaranty for the absolute certainty of philosophical knowledge, the noetical question emerges as to the means by which, and the limits within which, human knowledge is able to do justice to this great problem.  Descartes gave out the programme for all these various tendencies—­the mechanical explanation of nature, the absolute separation of body and soul (despiritualization of matter), thought the essence of the mind, the demand for certain knowledge, armed against every doubt, and the question as to the origin of ideas.  Its execution by his successors shows not only a lateral extension in the most various directions (the dualistic view of the world held by the occasionalists, the monistic or pantheistic view of Spinoza, the pluralistic or individualistic view of Leibnitz; similarly the antithesis between the sensationalism of Locke and Condillac and the rationalism of Spinoza and Leibnitz), but also a progressive deepening of problems, mediated by party strife which puts every energy to the strain.  What a tremendous step from the empiricism of Bacon to the skepticism of Hume,