A defense of contingent logical truths Michael Nelson • Edward N. Zalta

Abstract A formula is a contingent logical truth when it is true in every model
M but, for some model M, false at some world of M. We argue that there are such
truths, given the logic of actuality. Our argument turns on defending Tarski’s
definition of truth and logical truth, extended so as to apply to modal languages with
an actuality operator. We argue that this extension is the philosophically proper
account of validity. We counter recent arguments to the contrary presented in
Hanson’s ‘Actuality, Necessity, and Logical Truth’ (Philos Stud 130:437–459,
2006).