Empiricism, the name applied to a school in philosophy which admits of nothing as true but what is the result of experience, rejecting all a priori knowledge. It arose out of the system of Heraclitus which is elaborately refuted in the Theatetus of Plato, and was abhorrent to the lofty idealism of Socrates. Aristotle was an empiricist in so far as experience (empeiria) was to him the realisation of the ideal or form. The philosophy of Descartes established a kind of compromise between one part of knowledge regarded as innate, and another part as empirical or imparted from without. The founder of modern empiricism was Locke, who makes experience the basis of all knowledge, comprehending alike sensation and reflection. Condillac and the other French philosophes, rejecting reflection, pushed to an extreme the sensational side of Locke's philosophy, while Berkeley and Hume developed it on other lines to widely differing conclusions. The Common Sense school maintained that the ground of all knowledge was certain primary beliefs or first principles; Kant, on the other hand, found in the a posteriori facts of experience the first form of a consciousness which in its ultimate development must become a priori. The two elements are inseparably united; thus the a posteriori element, the facts, exist for us only under a priori conditions. This may almost be said to mark the turning-point of the new philo- sophy which has demonstrated that the distinction itself is not absolute, or rather that the distinction is itself transcended in the essential unity of knowledge.
The name empirie is applied also to one who depends on the accumulations of experience in any branch of knowledge, as in medicine, rather than on the strictly scientific methods of inference and deduction. See, on the one hand, MEDICINE, Vol. VII. pp. 115-16; and, on the other, QUACK DOCTORS.
The term Empirical Laws is applied to such as express relationships, which may be merely accidental, observed to subsist among phenomena, but which do not suggest or imply the explanation or cause of the production of the phenomena. They are usually tentative, and form stages in the progress of discovery of causal laws. Bode's law of the distances of the planets from the sun is an example.