Logical empiricism, also known as logical positivism, is a philosophical movement that emerged in the early 20th century, emphasizing that knowledge comes from sensory experience and viewing science as the only valid source of knowledge. It seeks to clarify language and meaningfulness through logical analysis, rejecting metaphysics and theology as meaningless. While influential in the development of analytic philosophy and the philosophy of language, logical positivism faced significant criticisms and is largely considered a historical movement by contemporary philosophers.