An Empiricism

1. A pursuit of knowledge purely through experience, especially by means of observation and sometimes by experimentation.
2. (philosophy) 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.)[1][2]
3. (medicine, dated) 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.

(medical practice founded on experience): charlatanry, quackery