I suppose I don’t see the justification of illusion over abstraction here. I can agree that they are abstractions, much as relativity is an abstraction and evolution is an abstraction; they are levels removed from what which they describe.
Here I will share what *I hold* to that seems _similar but distinct_: I hold that theory-theory is a good model for understanding how we understand things. We infer causation and structure, we infer objects and states and intentions; in short, we create theories and operate “as if” those theories are reality regardless of whether or not they correspond to reality.
But not only people do this; all creatures that interface with the world do this at some level; they need to in order to interact with anything, to have any responses. Some of these may be ‘encoded’ evolutionarily or be used “on the fly” during the living of a life. but it still holds.
So, a quorum of bacteria form a theory about whether or not to attack based upon the number of a particular chemical signal; it’s not a theory in the same sense of thinking in human words; but rather in an information sense of theory.