"If Can Can, If No Can No Can."

"Can can," as I see it, expresses that something is possible, "no can no can" that it is impossible. As the truth of things is approached, the less official the road to it seems. In a neat twist of affairs, if constructor theory is true, then the above phrase from Hawaii's pidgin may have the distinction of expressing the fundamental nature of reality.

In the "Science of Can and Can't," Dr. Chiara Marletto explores the nature of possibility as it relates to the traditional conception of physics. The main focus of her work concerns "the counterfactual properties of physical systems." Turns out that the possible and the impossible, also known as the counterfactual, have been neglected in physics. Marletto doesn't just say that this has been wrong, she says that our understanding of reality has been impoverished as a result.

As I was reading her book, I thought of another person deeply engaged with questions of counterfactuality, the philosopher David Lewis. Lewis pioneered the metaphysical domain of modal realism. His full acceptance of the reality of possible worlds was controversial, to say the least, among fellow analytic philosophers like Saul Kripke and Robert Stalnaker, neither of which minced words in saying how wrong headed Lewis was.

While there are some obvious differences between modal realism and constructor theory, top among these is that possible worlds are causally closed and can't interact with each other. Extended modal realism, developed by Takashi Yagisawa, does seem to take a step in the direction of the constructor theory by allowing objects to have modal and non-modal properties. Thus, what's possible is itself a modal property that can be categorized according to the type of possibility: logical, physical, metaphysical.

What fascinates me is how Marletto's work potentially provides a massive unification of domains traditionally thought to be separate. Here I'm thinking not just of the huge unification that she details between information theory and thermodynamics, which already is revolutionary, but a larger one that includes an extension and deepening of modality in general.