Moses Maimonides was a 13th century physician, philosopher, and rabbi. Some attribute this oath to Marcus Herz, a German physician and pupil of Immanuel Kant. Regardless of the real author or your religious persuasion, these words remind us why we do what we do.
The eternal providence has appointed me to watch over the life and health of Thy creatures.
May the love for my art actuate me at all time;
May neither avarice nor miserliness, nor thirst for glory or for a great reputation engage my mind;
For the enemies of truth and philanthropy could easily deceive me and make me forgetful of my lofty aim of doing good to Thy children.
May I never see in the patient anything but a fellow creature in pain.
Grant me the strength, time and opportunity always to correct what I have acquired, always to extend its domain;
For knowledge is immense and the spirit of man can extend indefinitely to enrich itself daily with new requirements.
Today he can discover his errors of yesterday and tomorrow he can obtain a new light on what he thinks himself sure of today.
Oh, God, Thou has appointed me to watch over the life and death of Thy creatures;
Here am I ready for my vocation and now I turn unto my calling.