"The saving of life overrides the commandments of the entire Torah; and he shall live by them and not die by them. Desecrate one Sabbath on his account so that he may keep many Sabbaths” (Yoma 85b
). This law is the watchword of Judaism...Maimonides, the master of conciseness, deviated from his regular manner and treated this issue with great elaborateness: “When such things have to be done, they should not be left to heathens, minors, slaves or women...They should rather be done by adult and scholarly Israelites. Furthermore, it is forbidden to delay such violation of the Sabbath for the sake of a person who is dangerously ill. For Scripture says: ‘which is a man do, he shall live by them’ (Leviticus 18:5
), that is to say, he shall not die by them. Hence you learn that the ordinances of the Torah were meant to bring upon the world not vengeance, but mercy, lovingkindess, and peace. It is of heretics who assert that this is nevertheless a violation of the Sabbath and therefore prohibited that Scripture says, ‘Wherefore I gave them also statutes that were not good, and ordinances whereby they should not live” (Ezekeziel 20:25).’” The teachings of the Torah do not oppose the laws of life and reality, for were they to clash with this world and were they to negate the value of concrete, physiological-biological existence, then they would contain not mercy, lovingkindness, and peace but vengeance and wrath. Even if there is only a doubtful possibility that a person’s life is in danger, one renders a lenient decision; and as long as one is able to discover some possible danger to life, one may use that doubt to render a lenient decision...This law that pikuah nefesh, saving a life, overrides all the commandments and its far-reaching effects are indicative of the high value which the halakhic viewpoint attributes to one’s earthly life — indeed they serve to confirm and nurture that value.
[Lawrence Kaplan translation]