ontological reductionism

Ontological reductionism is a philosophical view asserting that entities of one kind are identical to, or composed of, entities of a simpler or more basic kind. For example, the idea that physical bodies are collections of atoms is a form of ontological reductionism. This view has been widely accepted since the scientific revolution, particularly with advancements in molecular biology.12

While ontological reductionism focuses on what things are made of, methodological reductionism suggests that the behavior of entities can be explained by the behavior of smaller, more basic entities. Theoretical reductionism, on the other hand, proposes that older scientific theories can be logically derived from newer, more fundamental ones. However, extreme forms of reductionism, especially concerning the reducibility of biology and psychology to physics, have been viewed as misguided by many.23