Social constructionism or social constructivism is a sociological an psychological theory of knowledge that considers how social phenomena develop in particular social contexts. Within constructionist thought, a social construction (social construct) is a concept or practice which may appear to be natural and obvious to those who accept it, but in reality is an invention or artifact of a particular culture or society. Social constructs are generally understood to be the by-products (often unintended or unconscious) of countless human choices rather than laws resulting from divine will or nature. This is not usually taken to imply a radical anti-determinism, however. Social constructionism is usually opposed to essentialism, which defines specific phenomena instead in terms of transhistorical essences independent of conscious beings that determine the categorical structure of reality.