Life Is Paramount!

The Midrash (Devarim Rabbah 11:6) relates Moshe’s prayer to God: “Master of the Universe, if You do not bring me into the Land of Israel, allow me to be as the beasts of the field who eat grass, drink spring water, and see the world. Let my soul be like theirs.” The Holy One, Blessed is He, replied, “It is too much for you!” (Devarim 3:26). Moshe then said, “Master of the Universe, if not, allow me to remain in this world like the birds who fly to all four corners of the earth, gathering their food each day, and returning to their nest in the evening. Let my soul be like theirs.” 

A certain family once came to Rav Shach for advice. The mother was sick and the doctors recommended a dangerous operation whose chance of success was small. In any case, they said that she would never return to her former self. The family was devastated, and their question was whether they should agree to the operation.

He told them. “The only relevant factor is prolonging life. Even if the quality of life will be reduced and there will be what appears to be unnecessary suffering, life is paramount. We find that our master, Moshe, asked to remain alive even as a bird! What value can life as a bird have - he cannot fulfill mitzvah as a bird! Yet, one who knows that everything that HaShem created was created for His glory, and that eacb creature adds to the glory of Heaven in this world, knows the true value of each second of life, in whatever state!"

Rav Elazar Shach.“Rav Shach on Chumash.” Parashas Va’eschanan p. 215.