See reductionism in American Heritage Dictionary 4
(rĭ-dŭkˈshə-nĭzˌəm)
noun
An attempt or tendency to explain a complex set of facts, entities, phenomena, or structures by another, simpler set: “For the last 400 years science has advanced by reductionism … The idea is that you could understand the world, all of nature, by examining smaller and smaller pieces of it. When assembled, the small pieces would explain the whole”(John Holland).