Nietzsche Understood the Roots of Scientism

Strictly speaking, there is no such thing as science "without any presuppositions" . . . a philosophy, a "faith," must always be there first, so that science can acquire from it a direction, a meaning, a limit, a method, a right to exist . . . It is still metaphysical faith that underlies our faith in science.

Genealogy of Morals III.