El ensayo Ars Medica de John Locke, y la influencia de sus ideas médicas sobre la filosofía empirista

John Locke’s essay Ars medica of 1669, is presented, analyzed and translated into Spanish. This essay shows the medical problems that prompted Locke´s philosophy and provides essential clues to understanding the motives, aims and characteristics of the empiricist`s theory of knowledge. Ideas originated in medicine that profoundly influenced subsequent Locke`s works were: 1) Trust in the perfectibility of science and elucidation of the role that philosophical thinking could play. 2) Rejection of knowledge deduced from principles, hypotheses or maxims. 3) Reliance on a «plain historical method» for the production of knowledge, which tried to register facts descriptively, while abandoning the study of ultimate causes. 4) Use of a three-part classification of the sciences that enthrones semiotics, medical science par excellence, and defines it as a mere knowledge of the signs of things, that is not intended to discern either essences or substances. Locke, in his epistemology, applies to all scientific knowledge the medical theory of the signs of illnesses. He envisions all possible science as a mere descriptive knowledge of signs; and thinks that knowledge is probabilistic, analogous and pragmatic.