Our Gemara on Amud aleph discusses the famous moral dilemma of a circumstance where you must choose between another person’s survival or your own survival, such as you are in the desert with another person, and only have enough water for one person to survive. 

Ben Petora taught: It is preferable that both of them drink and die, and let neither one of them see the death of the other. Until Rabbi Akiva came and taught that the verse states: “And your brother shall live with you,” indicating that your life takes precedence over the life of the other. (The emphasis is on “with you”, so you come first.)

It is difficult to understand Ben Petora’s rationale, given that it is a general principle that the commandments of the Torah do not require martyrdom (Yoma 85b). And even though one must martyr himself instead of committing the fundamental sins of murder, idolatry and sexual immorality (ibid 82b), that is only via action, but through inaction. One cannot be compelled into martyr hood if his inaction would result in a violation of these three sins. This is because the rationale given by the Gemara is, “who is to say your blood is redder than your friend’s blood?”, and the other two sins are scripturally linked. Therefore, it is only logically valid to stop one from taking action, such as a scenario when by threat of death one is ordered to kill another. But if by being passive, another will die instead of him, his own life should take precedence (see Tosafos “Mah Rotzeach”, ibid 82a.) What then was Ben Petora’s reasoning? 

The Chazon Ish (YD 69) explains that there is a well known principle that temporary life is also sacred, thus one must violate the Shabbos even to prolong the life of someone who is terminally ill (Yoma 85a). Ben Petora’s argument is that you both must drink now, to stay alive now. The future is indeterminate and not relevant. 

I will add another explanation for Ben Petora’s position, albeit poetic and derush. Ben Petora uses an interesting phrase: “let neither one of them see the death of the other.” This extra point seems superfluous. I believe Ben Petora is adding an additional justification. The idea of surviving while watching his friend die is simply too painful and horrible to think of, that the Torah cannot expect a person to make such a painful decision. This would be similar to various rabbinic arguments that certain otherwise possible interpretations of law cannot be accepted because it is counter intuitive that the Torah would obligate something that runs against the ways of “pleasantness and peace”, see for example Succah 32a-b, and Yevamos 87b.)