Supervenience

Supervenience is a concept developed by philosophers to capture a way in which certain facts, events or properties rely or depend on others in a noncausal way. It is one way to capture the notion that certain phenomena seem to emerge from, or are determined by, others.

Consider an example. The movement of one snooker ball depends on the way it is hit, either by the cue or by another ball. This is the familiar causal notion of dependence. But now suppose the balls make a perfect ‘W’ shape on the table. That ‘W’ depends on the arrangement of the individuals balls. It isn’t that the balls’ arrangement causes the ‘W’ to exist. Rather, the balls and their arrangement constitutes, or makes up the ‘W’. Their individual arrangements, taken together, brings it about that there is a ‘W’ shape on the table. These are all intuitive but imprecise ways of capturing the noncausal relationship between the individual balls and the ‘W’. The technical term philosophers use for this relationship is supervenience. It was used by Hare, and was put centre stage first by Davidson, and then by Kim and Lewis. Section 1 will explore different ways to define ‘supervenience’.

Philosophers find the notion of supervenience useful because it can be used to describe and analyse a number of phenomena which seem to depend on other phenomena in an important, but noncausal, way. These might include: truth depending on reality; the mind depending on the brain; and moral and aesthetic truths depending on physical properties. Supervenience also provides a useful way to help clarify what is at stake in a number of debates, such as the internalist/externalist debate over mental content.