1. NATURAL PHILOSOPHY.—To philosophize concerning nature is, in a certain sense, to create nature—to raise it from the dead mechanism in which it had seemed confined, to inspire it with freedom, and transpose it into a properly free development. And what, then, is matter, other than mind which has become extinct? According to this view, since nature is only the visible organism of our understanding, it can produce nothing but what is conformable to a rule and an end. But you radically destroy every idea of nature just so soon as you allow its design to have come to it from without, by passing over from the understanding of any being. The complete exhibition of the intellectual world in the laws and forms of the phenomenal world, and, on the other hand, the complete conception of these laws and forms from the intellectual world, and therefore the exhibition of the ideality of nature with the ideal world, is the work of natural philosophy. Immediate experience is indeed its starting point; we know originally nothing except through experience; but just as soon as I gain an insight into the inner necessity of a principle of experience, it becomes a principle apriori. Natural philosophy is empiricism extended until it becomes absolute.
Schelling expresses himself as follows, concerning the chief principles of a philosophy of nature. Nature is a suspension (_Schweben_) between productivity and product, which is always passing over into definite forms and products, just as it is always productively passing beyond these. This suspension indicates a duality of principles, through which nature is held in a constant activity, and hindered from exhausting itself in its products. A universal duality is thus the principle of every explanation of nature; it is the first principle of a philosophic theory of nature, to end in all nature with polarity and dualism. On the other hand, the final cause of all our contemplation of nature is to know that absolute unity which comprehends the whole, and which suffers only one side of itself to be known in nature. Nature is, as it were, the instrument of this absolute unity, through which it eternally executes and actualizes that which is prefigured in the absolute understanding. The whole absolute is therefore cognizable in nature, though phenomenal nature only exhibits in a succession, and produces in an endless development, that which the true or real nature eternally possesses. Schelling treats of natural philosophy in three sections: (1) the proof that nature, in its original products, is _organic_; (2) the conditions of an _inorganic_ nature; (3) the reciprocal determination of organic and inorganic nature.