Gods and Demons: When Causation and Emergence Part Ways

The notion of emergence in philosophy is standardly taken to perform the metaphysical task of accommodating leveled structure: a 'vertical' relation between levels that explains the co-temporal dependence and novelty of e.g. biological entities with respect to their physical particles (life emerges from Carbon in the sense that it depends on Carbon atoms, but has a sort of higher-level autonomy). However, many authors have alternatively argued for a diachronic notion of emergence, where the relation is 'horizontal' in the sense that it is between same-level, but temporally successive, states. Wilson (2024) has recently put forward a challenge: what is the difference between diachronic emergence and causation? If there is no difference in the metaphysical task performed, there is no reason to take diachronic emergence seriously. In this paper, we show that there are at least two (non-mutually exclusive) different ways to characterize diachronic emergence as a determinative relation clearly distinct from causation: the first criterion is epistemic (with ontological import), the second is strictly ontological. We also provide concrete examples from the philosophy of science and show cases of the fruitfulness of this metaphysical notion.