I think I know what reductionism and emergentism are but have no ideas about supervenience.

As I understand it reductionism means explaining more complicated systems by reducing them to merely the interplay of less complicated systems. An example would be trying to explain psychological processes purely in terms of electrical or biochemical activity in the brain. So psychological phenomena are explainable using biology, biological phenomena are explainable using chemistry, chemical phenomena are explainable using physics, physical phenomena are explainable using mathematics.

Emergentism on the other hand says that beyond a certain level of complexity something new emerges which has to be explained in its own terms and cannot be explained as the interplay of less complex systems. In other words it says you have to explain psychological processes in psychological terms, not as electrical or biochemical activity in the brain. You have to explain psychological phenomena in psychological terms rather than biological ones, biological phenomena in biological terms rather than chemical ones, etc.

As I said, I don't know where supervenience comes in. Presumably something to do with supervening. More complex systems replace less complex ones, perhaps?

Bingley

Bingley