The Republic by Plato Part 1 Page 51

similar liability to fault or defect, and does every art require another supplementary art to provide for its interests, and that another and another without end? Or have the arts to look only after their own interests? Or have they no need either of themselves or of another? — having no faults or defects, they have no need to correct them, either by the exercise of their own art or of any other; they have only to consider the interest of their subject-matter.

For every art remains pure and faultless while remaining true — that is to say, while perfect and unimpaired. Take the words in your precise sense, and tell me whether I am not right.

Yes, clearly.

Then medicine does not consider the interest of medicine, but the interest of the body?