Generative science

I’m thinking about writing another book. I won’t disclose the title or topic yet, but there’s a bit of research for it I think can be usefully crowdsourced, and may also give a clue about the book for those of you interested.

I’ve written before about the difference between descriptive and generative theories. To recap and simplify, a descriptive theory accounts for what is; a generative theory finds causal regularities beneath a descriptive account and predicts consequences not yet observed.

Now I want to zero in on a parallel difference among entire sciences. Some scientific fields – like, say, evolutionary biology – are tremendously productive of models and insights that can be applied elsewhere. On the other hand, some other sciences – like, say, astronomy – seldom export ideas or models.

Note that while it is appropriate to think of sciences that export lots of ideas as ‘generative’, the class of sciences that don’t are not merely descriptive. Astronomy, for example, has lots of generative theory inside it; astrophysics, for example makes predictions about stellar spectra and elemental abundances. But astronomy as a whole is not generative because none of its theory really informs anything outside astronomy.

So I’m going to start with a (non-exhaustive) list of scientific fields, indicating roughly how generative I think they are and what if anything they export. I invite additions and corrections from my readers.

Evolutionary biology – extremely generative. Principal exports: evolution by selective pressure on random variation, adaptive radiation, genetic drift, mutation, and many others.

Mathematics – not an empirical science but extremely generative nevertheless. All kinds of abstract mathematical models end up suggesting applied-math models of the real world with interesting testable consequences.

Economics – highly generative. Principal exports: supply/demand equilibria, satisfaction under constraint, implicit knowledge, deadweight losses, search costs, coordination overhead, rational ignorance.

Linguistics – not very generative at all except for a small corner near psycholinguistics that exports some provocations about the relationship between thought and representation.

Physics – highly generative. Principal exports: conservation laws, principles of least action, entropy, state spaces, symmetry and symmetry-breaking, energy levels.

Astronomy – gorgeous, but almost completely non-generative.

Geology, zoology, agronomy – non-generative

Additions? Corrections?