Emergentism

Emergentism is the philosophical position that higher-level phenomena arise from lower-level processes yet are not reducible to those processes. Emergent properties are typically described as novel relative to their constituents, appearing only at certain levels of organization and, in some accounts, not fully predictable from the properties of the parts.

A common distinction is between weak and strong emergence. Weak emergence holds that higher-level phenomena can in principle be derived from or explained by lower-level laws, though such derivations may be computationally intractable or practically impractical. Strong emergence contends that certain properties are genuinely novel in a way that cannot be explained or predicted even in principle from the underlying microstate, sometimes with the claim that they have causal powers that influence lower levels (downward causation).

Ontological versus epistemological emergentism further differentiates positions. Ontological emergentism maintains that emergent properties are real, irreducible features of the world with objective existence. Epistemological emergentism maintains that emergent features are real but are irreducible only to our knowledge or descriptions, not to the underlying ontology.

In philosophy of mind, emergentism is often allied with non-reductive physicalism: mental states are real properties of physical systems but are not reducible to specific brain microstates. In science, emergentism is used to describe complex systems where collective behavior, phase transitions, or organizational properties (such as life, social dynamics, or consciousness) arise from interactions among simpler components.

Critics argue that emergentism sometimes lacks clear criteria for what makes an emergence genuine and may reintroduce causal or ontological issues that reductionism seeks to avoid. Nonetheless, emergentism remains influential in debates about explanation, causation, and the nature of scientific laws.