In antiquity, sick or disabled children were often left to die in the open, and even infanticide was not unusual up until the 20th century. These morally questionable practices were at least partly informed by the heritage of our Greek ancestors, who obligated physicians to not provide treatment of no perceived benefit. Hippocrates wrote:

And Plato in The Republic advised the physician:

Following along with our rapid advancement in the biological understanding of human health and disease and our vastly improved ability to effectively treat “inner sickness,” our normative ideas about benefit, harm, and misery have evolved. Nowadays, because of an abundance of resources available in the most economically developed countries, it is often medicine's first instinct to try to save the seriously ill or disabled before we start to worry about contributing to unacceptable suffering or prolonging misery.