I want to briefly comment on and recommend this paper by Takeshi Yagisawa called "Modal Realism with Modal Tense" (HT: OPP). It explores the parallels between modal and temporal metaphysics, and suggests that modal realists would benefit from treating the possible and the actual as tenses, in the manner of past and present tense, respectively.
Modal realism can create terminological and conceptual ambiguities which leave it vulnerable to criticism. If we speak of a (metaphysically) possible talking donkey and an actual mute donkey, how is it that the possible donkey is “real” if it isn’t “actual”? So, for the verb denoting reality we’re using (e.g. “is” or “exists”), we should consider creating two modal tenses. The possibility tense is an analog of the past tense; the actuality tense is an analog of the present tense. There is much less ambiguity or confusion when we say “dinosaurs existed”. Existing in the past tense is something we have an intuitive feel for (this is not to say philosophers don’t argue about the ontological status of past, present and future events/objects -- they do it all the time -- it’s just that the modality discussion suffers in comparison due to lacking the built-in toolkit of having tenses for words like “exist”).
There are many more subtleties to this idea than I will mention here and Yagisawa unpacks and presents them carefully. An interesting idea he discusses is a comparison of 2 approaches to modality to 2 parallel views of temporality as follows. If one views the possible and actual modes of reality in an even-handed or egalitarian fashion in the manner of David Lewis, this is analogous to the 4-dimensional or eternalist view of temporality, where different points in time all exist in an even-handed way. If one views the actual as deserving to be called “real” and wish to downgrade the reality of the possible (as in the view traditionally called “Actualism”), this is in the same spirit as presentism, which likewise displays a “chauvinism” in viewing the present as having an exclusive claim on reality.
I have been using the terms abstract and concrete to characterize the possibilities and the actualized events of our world, respectively. I think this is still OK as long as I can communicate it with some context. The appeal of using modal tenses is that it provides another way to introduce a primitive distinction to characterize the possible and actual without requiring either total even-handedness or a deflation of the possible. This was a thought-provoking paper.