empiricist

An empiricist is a proponent of empiricism, a theory of knowledge that emphasizes sensory experience as the source of most or all reliable knowledge. Empiricists hold that ideas and beliefs originate in impressions gathered through observation and experiment, and that reasoning should be grounded in evidence rather than innate ideas or purely a priori speculation. The term derives from the Greek empeiria, experience.

Historically, empiricism has ancient antecedents in Aristotle’s emphasis on systematic observation, but it is most associated with early modern philosophers such as Francis Bacon, who promoted inductive reasoning and experimental method; John Locke, who argued that the mind begins as a blank slate; and later George Berkeley and David Hume, who examined the limits of knowledge based on impressions and habit. Immanuel Kant later argued that knowledge begins with experience but also requires a priori structures, complicating pure empiricism.

In science, empiricism underpins the use of observation, measurement, and experiment to test hypotheses. It contrasts with rationalist approaches that prioritize deduction from innate ideas. Empiricist methods have helped shape the development of the scientific method, though debates about induction, the problem of justification, and the reliability of sense data continue to be central to the philosophy of science.

In addition to epistemology, the term has historical usage in medicine; the Empiric school of ancient Greek medicine emphasized practical experience in treatment rather than theoretical explanation. The modern use of the term generally refers to a stance within philosophy or sciences that privileges experience as the basis of knowledge.