Empiricism

In philosophy generally, empiricism is a theory of knowledge emphasizing the role of experience, especially sensory perception, in the formation of ideas, while discounting the notion of innate ideas.

In the philosophy of science, empiricism is a theory of knowledge which emphasizes those aspects of scientific knowledge that are closely related to experience, especially as formed through deliberate experimental arrangements. It is a fundamental requirement of scientific method that all hypotheses and theories must be tested against observations of the natural world, rather than resting solely on a priori reasoning, intuition, or revelation. Hence, science is considered to be methodologically empirical in nature.

The term "empiricism" has a dual etymology. It comes from the Greek word εμπειρισμός, the Latin translation of which is experientia, from which we derive the word experience. It also derives from a more specific classical Greek and Roman usage of empiric, referring to a physician whose skill derives from practical experience as opposed to instruction in theory.