 Positivism is closely related to reductionism, in that both involve the belief that "entities of one kind... are reducible to entities of another," such as societies to configurations of individuals, or mental events to neural phenomena.It also involves the contention that "processes are reducible to physiological, physical or chemical events," and even that "social processes are reducible to relationships between and actions of individuals," or that "biological organisms are reducible to physical systems.