Ética, Parte IV, Proposición 38
Whatsoever disposes the human body, so as to render it capable of being affected in an increased number of ways, or of affecting external bodies in an increased number of ways, is useful to man; and is so, in proportion as the body is thereby rendered more capable of being affected or affecting other bodies in an increased number of ways; contrariwise, whatsoever renders the body less capable in this respect is hurtful to man.
Demostración
Whatsoever thus increases the capabilities of the body increases also the mind's capability of perception (II. xiv.); therefore, whatsoever thus disposes the body and thus renders it capable, is necessarily good or useful (IV. xxvi. xxvii.); and is so in proportion to the extent to which it can render the body capable; contrariwise (II. xiv., IV. xxvi. xxvii.), it is hurtful, if it renders the body in this respect less capable. Q.E.D.
Benedict de Spinoza, The Ethics (Ethica Ordine Geometrico Demonstrata), traducido del latín por R. H. M. Elwes.
Publicado por primera vez en The Chief Works of Benedict de Spinoza, vol. II (London: George Bell and Sons, 1884).
Esta traducción es de dominio público en Estados Unidos, donde se publicó en 1884, y en cualquier lugar donde el plazo de derechos de autor sea la vida del autor más 100 años o menos; su traductor murió en 1892.
La división en unidades, los títulos y la ubicación de las notas son de este sitio.
Texto digital: Project Gutenberg eBook #3800