It is, perhaps, the defining characteristic of ‘scientism’ to claim that all truth is susceptible to scientific enquiry, and that only truths discovered by the scientific method are true at all.
William Lane Craig, in a 1998 debate with atheist Peter Atkins, responded to this claim by listing five types of truth that are not scientifically demonstrable:-
1. Logical and mathematical reasoning;
2. Metaphysical truths, such as the existence of other minds, or that the external world is real, or that the past did not come into being five minutes ago;
3. Ethical beliefs, such as statements of value;
4. Aesthetic judgments;
5. Science itself has to make many unprovable assumptions (such as the constancy of the speed of light).