a philosophy, a faith, must always exist first to enable science to gain thereby a direction, a meaning, a limit and method, a right to existence.
 Friedrich Nietzsche, On the Genealogy of Morality (1887). copy citation

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Author Friedrich Nietzsche
Source On the Genealogy of Morality
Topic philosophy science
Date 1887
Language English
Reference
Note Translated by Horace B. Samuel
Weblink https://en.wikisource.org/wiki/The_Genealogy_of_Morals

Context

“But what forces it into that unqualified will for truth is the faith in the ascetic ideal itself, even though it take the form of its unconscious imperatives,—make no mistake about it, it is the faith, I repeat, in a metaphysical value, an intrinsic value of truth, of a character which only warranted and guaranteed in this ideal (it stands and falls with that ideal) . Judged strictly, there does not exist a science without its "hypotheses," the thought of such a science is inconceivable, illogical: a philosophy, a faith, must always exist first to enable science to gain thereby a direction, a meaning, a limit and method, a right to existence. (He who holds a contrary opinion on the subject—he, for example, who takes it upon himself to establish philosophy "upon a strictly scientific basis"—has first got to "turn upside-down" not only philosophy but also truth itself—the gravest insult which could possibly be offered to two such respectable females!)” source