Supervenient

Supervenient is a term used in philosophy, particularly in the philosophy of mind and ethics, to describe a relationship between two sets of properties. When one set of properties supervenes on another, it means that the first set of properties is entirely determined by the second set. If two things are identical with respect to the supervening properties, they must also be identical with respect to the properties upon which the first set supervenes. In simpler terms, there cannot be a change in the supervening properties without a change in the base properties.

For example, in the philosophy of mind, it is often argued that mental properties supervene on physical properties. This means that if two individuals have exactly the same physical brain states, they must also have exactly the same mental states. Any difference in consciousness, thoughts, or feelings would necessitate a difference in their underlying physical makeup. Similarly, in ethics, it is sometimes proposed that moral properties supervene on natural properties. This implies that if two situations are identical in all their natural, non-moral respects, they must also be identical in their moral respects. A change in whether an action is right or wrong would require a change in the natural facts of the situation.

The concept of supervenience is crucial for understanding various philosophical positions, such as physicalism and non-reductive materialism. It provides a way to talk about the dependence of one level of reality on another without necessarily claiming that the higher level can be reduced to the lower level. It is a formalization of the intuition that the way things are at a more fundamental level determines the way they are at a higher level.