Make a habit of two things: to help; or at least to do no harm.

First do no harm

There are in fact two things, science and opinion; the former begets knowledge, the later ignorance.

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.

Make a habit of two things: to help; or at least to do no harm.

Whenever a doctor cannot do good, he must be kept from doing harm.