The physician must be able to tell the antecedents, know the present, and foretell the future — must mediate these things, and have two special objects in view with regard to disease, namely, to do good or to do no harm.
Declare the past, diagnose the present, foretell the future; practice these acts. As to diseases, make a habit of two things–to help, or at least to do no harm.
First of all a natural talent is required; for when Nature opposes, everything else is in vain; but when Nature leads the way to what is most excellent, instruction in the art takes place.
