empiricism

A pursuit of knowledge purely through experience, especially by means of observation and sometimes by experimentation.

A doctrine which holds that the only or, at least, the most reliable source of human knowledge is experience, especially perception by means of the physical senses. (Often contrasted with rationalism.)

A practice of medicine founded on mere experience, without the aid of science or a knowledge of principles; ignorant and unscientific practice; the method or practice of an empiric.