the romance of the counterfactual

Wed, 05 Aug 2026 00:00:00 +0000

Had wanted to write something about a personal, quasi-literary takeaway from my time in graduate school: the observation that Kripke's possible-worlds semantics of modal logic points up the central feature of the human condition: we alone among earthly animals are aware of what might be and what might have been.

Modal logic treats of "states" (states of anything; the notion can be harnessed to sundry domains). One could define the states of one's modal world, for instance, to be the stages of a four-stroke gasoline engine or the states a computer program can be in as it runs—or, really, anything you like that has an interesting sequential, state-like structure.

The modality of a state is whether it is possible, actual, necessary, or impossible. A possible state may or may not be the case. An actual state is trivially possible, which rings true intuitively: it's not just possible but happens to be actual. A necessary state is not only actual and possible but could not be otherwise. An impossible state is none of these and necessarily cannot be possible, let alone actual or necessary.

Although modality finds extensive use in computer science, the classic application of possible-world semantics in philosophy since Kripke has been time. States of affairs at different points in time can be laid out in the imagination and discussed in light of their possibility, actuality, and necessity. Kripke says something special about actuality and necessity that opens up a whole can of worms regarding metaphysics that we won't go into here, but what struck me about this seemingly esoteric subject was that focusing on the modality of events—if not outright obsessing about them—is so commonplace that we might say it's how we humans live our lives. It's what makes us human: we are the modalist species.

Faculties and emotions related to this phenomenon:

memory
planning
regret
hope
grief
denial

The list could go on and on, but it's all about contemplating things that might (or might not) have been in the past, how things are now, or what one might cause to be through one's actions.

Modalist thinking about the past is especially poignant, since most of us have our regrets, and many of us dwell on them to the detriment of our health and happiness.

The modal point about actions and events in the past is that they are actual and therefore irreovocable. No backsies! They may also be necessary in more than one sense, which may not be the same as saying they must have been necessary at the time they happened. It could still be that they were up in the air when they occurred (or slightly before), but now that they're a done deal, they're a necessary feature of the spacetime grid, because they can't be rerun. This is a controversial assertion, but I don't think anyone claims that past events can be undone unless they're willing to entertain the possibility of time travel.

long and short

the romance of the counterfactual