Full Idea
There belongs to truthfulness not only the avoidance of lying but also that other kind of attachment to truth which has to do with its preservation and pursuit.
Gist of Idea
We should speak the truth, but also preserve and pursue it
Source
Philippa Foot (Utilitarianism and the Virtues [1985], p.74)
Book Reference
Foot,Philippa: 'Moral Dilemmas' [OUP 2002], p.74
A Reaction
This is truth as a value, rather than as a mere phenomenon of accurate thought and speech. The importance of 'preserving' the truth is the less common part of this idea.