Full Idea
The falseness of a judgement is to us not necessarily an objection to a judgement. To what extent is it life-advancing, life-preserving, species-preserving. Our fundamental tendency is to assert that our falsest judgements are the most indispensable.
Gist of Idea
We shouldn't object to a false judgement, if it enhances and preserves life
Source
Friedrich Nietzsche (Beyond Good and Evil [1886], §004)
Book Reference
Nietzsche,Friedrich: 'Beyond Good and Evil', ed/tr. Hollingdale,R.J. [Penguin 1973], p.17
A Reaction
This is the standard objection to pragmatism, that what is false may still be useful, and that clever blighter Nietzsche embraces the idea!