This is a metaphysics blog, but while I am on the topic of verisimilitude I thought it might be worth mentioning two other philosophical purposes for which it might help to take verisimilitude seriously, for which to my (limited) knowledge it has not yet played a role in the literature:
1. Might verisimilitude be the norm of assertion, rather than e.g. truth? If it is, this might give us a reason to suppose that people are speaking literally when indulging in harmless idealisations, or glossing over details for a conversational purpose (at least some of the time, at any rate). Or if it is not verisimilitude, might it be something like known verisimilitude (rather than knowledge tout cour), or justified belief in verisimilitude?
2. Is verisimilitude a problem for minimalism and deflationism about truth? Suppose one thought there was not much more to “snow is white” being true than snow being white (and perhaps the sentence meaning what it does). What, then, is it for “snow is white” to be close to true? One might suggest that it is snow being close to white. But that is not the only way “snow is white” could be close to true, it seems to me. If something close to snow was white, but snow was all transparent, the claim might still be close to true, especially if the near-snow was ubiquitous. If no snow was white right now, even though it nearly always was and nearly always will be, the claim might be thought to be close to true. And of course even if “snow is close to white” captures a necessary and sufficient condition for “’snow is white’ is close to true”, there may be plenty of other examples which are not so easily captured.
The worry is that to explain being close to truth one might need to say something non-minimal about what it is to be true. One way to avoid this without playing “hunt the paraphrase” would be to introduce an operator into the object language (or claim it was there all along) so that we can say, without truth, exactly what is the case whenever a claim is close to true. E.g. the operator “kind of”
“Snow is white” is close to true iff KIND OF: snow is white.”
Of course, we might still wonder whether such an operator is understood without recourse to thinking about truth and closeness of claims to that standard.