This paper examines our pre-theoretic conception of non-supernaturalism; the thesis that all that exists is natural. It is argued that we intuitively take this thesis to be a substantive, non-dogmatic, empirically justified, not merely contingent truth. However, devicing an interpretation of non-supernaturalism that captures all aspects of this intuition is difficult. Indeed, it is found that this intuition conflates the strong inferential scope of a metaphysical claim with the modest justificatory requirements of an empirical matter of fact. As such, non-supernaturalism, in its pre-theoretic form, contains an internal tension that must be navigated whenever the thesis features in systematic thinking.