Not all foundations are equal. This chapter introduces the three-tier taxonomy at the heart of Foundations of Reason: axioms (what you cannot think without), presuppositions (what you cannot live without), and principles (what works well enough to earn its place). The grammar that structures everything that follows.

You have been standing on axioms your entire life—you just haven't noticed. This chapter shows why foundations matter, what happens when axioms stay hidden, and the difference between named and smuggled commitments. The first step toward examining the ground beneath your own thinking.