ABSTRACT
A necessary proposition is true by virtue of the nature of things; it expresses the essence of things. An analytic proposition is true by virtue of its meaning or, when in the subject-predicate form, if the predicate is contained in the meaning of the subject. An a priori proposition is one which can be known without any appeal to the particular facts of experience. These crude dictionary definitions are sufficient to bring out the distinction that necessity is a metaphysical concept, analyticity a linguistic concept, and apriority an epistemological concept. The writings of Leibniz seem to suggest a curious and interesting theory of definitions. These definitions should enable us to make the decomposition or analysis of a complex concept into the simple ones after the fashion of the decomposition of a natural number into its prime factors. Frege makes an attempt to state accurately what earlier writers, Kant in particular, have meant by the analytic-synthetic distinction.
