Methodological naturalism is the most justified inquiry principle available—but it is a principle, not a presupposition, and not a metaphysical claim. This chapter explains exactly what it says, what it doesn't say, why it works, and where it reaches its limits. The single most important distinction: methodological vs. metaphysical naturalism.

Reality, causality, and induction are not three separate bets—they are facets of a single stance: that the world is knowable. This chapter examines each in turn, shows why none can be proven, names the pragmatic loop that grounds them all, and invites you to hold these commitments consciously rather than blindly.