Inquiry on the origins of concepts, as we said, is a task specific to psychology. In contrast, the theory of knowledge is limited to the research and justification of “the most general and immediately evident truths” (Stumpf, 1891, p. 501), such as laws and axioms necessary for knowledge. Yet, these axioms are nothing but propositions that we assume to be true and necessary, and they have their origin in the content of a specific class of psychical functions, namely judgments. Since the contents