 It follows that a philosophical system must begin with a single first principle, which “determines” all the other propositions of the system. (Here again, there is a certain obscurity in Reinhold’s claim, inasmuch as he insisted that the first principle “determines” only the “form” and not the “content” of all the other, subordinate propositions, yet he also described the relationship between the first principle and the subordinate principles as a “syllogism,” in which the latter are “derived” from the former.) Only if propositions are logically related to one another in this manner can they constitute a “system.” A system with two or more “first principles” is not a system at all, but several different systems. As for the completeness problem, Reinhold’s implicit solution seems to have been to seek an a priori first principle that could be known in advance to encompass the entire domain of experience, and hence of philosophy.