Responsum: On a Set Lifetime

The answer, in our opinion, is that there is no predetermined time [of death] and that animals live so long as a replacement for their essential moisture, which disintegrates, is replenished, such that it remain in its state and does not decay, as Galen pointed out that the cause of death is the decay of natural heat equilibrium. Its decay may be brought about either by internal causes that set it into motion or by external causes that come to it. [ . . . ]

Death may also occur as a consequence of [the body’s] encountering hard objects, whether by being cut by some such [object] as a sword or sharp iron tools, which sever [the body’s] unity, or by being shattered by some such [object] as a stone or other solid object, if they were to encounter the animal’s body [either] by striking it violently [or] by falling upon it from an elevated place. [Given that the matter is thus as we have described it,] so long as a person is careful [to avoid] these causes that we have described, then no impediments should cut his [life short] and he should ultimately end [his life] with a natural life span. [ . . . ]

We will first present the legal¹ evidence because of its nobility and magnanimity and because it is the peak to which [a person] may arrive after [having mastered] the practical sciences, which are the mathematical, natural [i.e., physics], and divine [i.e., metaphysics] [sciences], by means of the logical [sciences], as they are what bring [a person] to ultimate bliss. [God] said: When you build a new house, you shall make a railing for your rooftop (Deuteronomy 22:8). This verse is evidence that being alert and prepared to protect [oneself] from being exposed to the risks of destructive matters repels their occurrence. If being alert were not beneficial in repelling accidents, then this commandment would not have [any] benefit, as no harm would be repelled by means of it, since if [God] were to have decreed that something fall from this rooftop, then there would be no benefit whatsoever in a railing, and it would end up being in vain and of no avail. But we see that when He, may He be exalted, called for [a person to build] a railing, He clarified that being alert is beneficial and that being prepared repels [harm]. This contradicts whoever says that life in this world [ends] at an ordained predetermined time. [ . . . ]

Irrefutable evidence for this opinion of ours is His saying: In forty more days, Nineveh will be upturned (Jonah 3:4), but when they repented, He forgave them, as He said: And the people of Nineveh had faith in God (Jonah 3:5), [and He] said: And God saw their actions, that they repented (Jonah 3:10). If the measure of their predetermined time [of death] was in forty [days], then it was inevitable that repentance would not save them and that they would perish. On the other hand, if their predetermined time [of death] was measured to whatever time after repentance at which they were to end [their life], then their disobedience should not have harmed them, even if they were to have persisted in it and not repented. This is evidence, then, that life in this world is not ordained such that no interrupter may cut it [short].