Full Idea
Optimalists say that negative truths are 'true by default' (having the opposite truth value of p), and universal truths are too. Universal truths are equivalent to negative existential truths, which are true by default.
Clarification
¬∃x¬Fx → ∀xFx
Gist of Idea
Optimalists say that negative and universal are true 'by default' from the positive truths
Source
Fraser MacBride (Truthmakers [2013], 2.2)
Book Reference
'Stanford Online Encyclopaedia of Philosophy', ed/tr. Stanford University [plato.stanford.edu], p.18
A Reaction
The background idea is Wittgenstein's, that if p is false, then not-p is true by default, without anyone having to assert the negation. This strikes me as a very promising approach to truthmaking. See Simons 2008.