In trying to make sense of Hoel’s theory of “causal emergence”, summarized here, I get stuck thinking about the semantics. What is a cause? What if we taboo it, similarly to how e-prime taboos “to be” verbs? The reductionist approach seems to focus on the events which seem to be the beginning of a chain of events which lead to the event in question. This is something like an attempt at pure objectivity. Alternatively, the causally emergent approach seems to seek the best predictor for a given event — the thing that provides the most information — and then treats that as a “causally emergent, ontologically real” thing that “actually exists”. Scary words. I do like this idea of gesturing towards the inherent limits of human subjectivity — we are limited by what we can observe, which appears inherently subjective. Furthermore, there are limits of computability, and maybe even something like comprehensibility. What value is a reductive theory of the universe if we lack the tools to apply it at the scales we care about? We don’t try to catch baseballs with quantum mechanics, in the words of a friend. An explanation that is true, in some sense of the word, is not necessarily useful.
What causes a set of dominos to fall over? A reductive model is forced to explain the physics back to the beginning of the universe. A causally emergent model may be willing to model it back to the point where local complexity is maximized (or something like that, *waves hands around*): the mind of the nearby human who was feeling restless this afternoon. What causes humans to act? Models can be built here, too. We can tease apart the best predictors for a given event: when they had their last meal, environmental cues, genetics, etc. Is this the actual cause? Depends on what you mean…
Also published on Medium.