Full Idea
Both the earliest and most recent philosophers are all oblivious of how much the will to truth itself first requires justification: here there is a gap in every philosophy - how did this come about?
Gist of Idea
Philosophers have never asked why there is a will to truth in the first place
Source
Friedrich Nietzsche (On the Genealogy of Morals [1887], III.§24)
Book Reference
Nietzsche,Friedrich: 'On the Genealogy of Morals/ Ecce Homo', ed/tr. Kaufmann,Walter [Vintage 1969], p.152
A Reaction
This seems to me a meta-philosophical question which will lead off into (quite interesting) cultural studies and (trite) evolutionary theory. Truth isn't a value, it is the biological function of brains.