Abstract
Monism is a doctrine that claims to deduce the entire system of knowledge from one first principle. It must be a system of a mutually connected propositions that are obtained by a methodologically reliable unfolding of one original proposition accepted as self-evident and unquestionable. Modern philosophy in its rationalist version, beginning with Descartes, tends precisely to this kind of monistic construction of the system of knowledge from a first principle. The striving toward monism is demonstrated most clearly in Spinoza's and Fichte's systems. Spinoza's original principle is substance-that which exists by itself and is comprehended through itself. Fichte replaces substance by the Absolute Subject, the Absolute I, which by an act of self-positing brings itself into being and defines itself only by itself. In one and the other, all the determinations of the system must follow from the original principle with indisputable necessity. It is this logical necessity that claims to be the pure image of the scientific spirit that was valued so highly by modern European thought