ἀσκεῖν περὶ τὰ νοσήματα δύο, ὠφελεῖν ἢ μὴ βλάπτειν –> as to diseases, make a habit of two things — to help, or at least, to do no harm
— Hippocrates, Epidemics, Book I, Ch. 2
https://el.wikisource.org/wiki/%CE%95%CF%80%CE%B9%CE%B4%CE%B7%CE%BC%CE%B9%CF%8E%CE%BD?match=enhttps://el.wikisource.org/wiki/%CE%95%CF%80%CE%B9%CE%B4%CE%B7%CE%BC%CE%B9%CF%8E%CE%BDVariant translation: 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.
Paraphrased variants: Wherever a doctor cannot do good, he must be kept from doing harm.
Viking Book of Aphorisms: A Personal Selection (1988) by W. H. Auden and Louis Kronenberger, p. 213.
https://en.wikiquote.org/wiki/Hippocrates