do no harm

Etymology
.

Verb

 * 1)  To perform no actions which will be injurious or in any way unfavorable to another person, regardless of whether one does anything of positive benefit for that other person.

Usage notes

 * In medicine, often used in the imperative mood as a formulation of the Hippocratic Oath.
 * In philosophy, often used in the imperative mood as a formulation of the moral minimum.