Supervenience
Etymology
Latin supervenire, from super- + venire to come — more at come
- Date: circa 1648
Definition
- to follow or result as an additional, adventitious, or unlooked-for development
Description
In philosophy, supervenience is a kind of dependency relationship, typically held to obtain between sets of properties. According to one standard definition, a set of properties A supervenes on a set of properties B, if and only if any two objects x and y which share all properties in B (are "B-indiscernible") must also share all properties in A (are "A-indiscernible"). That is, A-properties supervene on B-properties if being B-indiscernible implies being A-indiscernible. The properties in B are called the base properties (or sometimes subjacent or subvenient properties), and the properties in A are called the supervenient properties. Equivalently, if two things differ in their supervenient properties then they must differ in their base properties. To give a somewhat simplified example, if psychological properties supervene on physical properties, then any two persons who are physically indistinguishable must also be psychologically indistinguishable; or equivalently, any two persons who are psychologically different (e.g., having different thoughts), must be physically different as well. Importantly, the reverse does not follow (supervenience is not symmetric): even if being the same physically implies being the same psychologically, two persons can be the same psychologically yet different physically: that is, psychological properties can be multiply realized in physical properties.
Supervenience has traditionally been used to describe relationships between sets of properties in a manner which does not imply a strong reductive relationship.[1] For example, many hold that economic properties supervene on physical properties, in that if two worlds were exactly the same physically, they would also be the same economically. However, this does not entail that economics can be reduced in any straightforward way to physics. Thus, supervenience allows one to hold that "high-level phenomena" (like those of economics, psychology, or aesthetics) depend, ultimately, on physics, without assuming that one can study those high-level phenomena using means appropriate to physics.
