Leon Kass, MD, PhD, Addie Clark Harding Professor at the University of Chicago, in a Winter 1989 Public Interest article "Neither for Love nor Money: Why Doctors Must Not Kill," stated:

“The prohibition against killing patients… stands as the first promise of self-restraint sworn to in the Hippocratic Oath, as medicine’s primary taboo: ‘I will neither give a deadly drug to anybody if asked for it, nor will I make a suggestion to this effect’… In forswearing the giving of poison when asked for it, the Hippocratic physician rejects the view that the patient’s choice for death can make killing him right. For the physician, at least, human life in living bodies commands respect and reverence–by its very nature.”

Winter 1989