Emergence
Overview
Emergence is the appearance of properties in a system that none of its components has on its own, and that arise from the organisation and interaction of those components. Wetness is not a property of any single water molecule; it is a property of a great many of them together. A traffic jam is not a property of any car. A mind is not a property of any neuron.
A distinction is sometimes drawn between weak emergence (the higher-level property is fully determined by, and in principle derivable from, the lower-level facts, even if the derivation is impractical) and strong emergence (the higher-level property is genuinely new and not derivable even in principle). I accept the first and see no evidence for the second.
Notes
- Emergence is not magic and it is not an explanation on its own. To say that consciousness "emerges" from the brain is to say where to look, not to say how it works. The work of explanation still has to be done. See Consciousness.
- It is the answer to the Composition Fallacy and the Division Fallacy: what is true of the parts need not be true of the whole, and the other way round.
- Several of my positions describe emergent phenomena: consciousness from neural activity, morality from the interaction of self-interested agents (Objective morality), and the appearance of design from natural selection. In each case the appeal to emergence replaces an appeal to a designer or lawgiver, and in each case it does so with a mechanism that can be studied.