 He then extended this distinction to cover other elements of axiomatic theories. Subjectively, definitions are considerations that acquaint us with the meanings of certain words, while objectively, a definition indicates the parts and structure of a complex concept. Subjectively, some words do not require definition, because their meanings are already clearly understood, while objectively, some concepts cannot be defined because they are simple, i.e., have no parts. Similarly, an axiom or principle in the subjective sense is a proposition whose truth is evident to us, while in the objective sense an axiom is simply an indemonstrable truth from which other truths may be deduced.