Lecture 18: The Badness of Death, Part III; Immortality, Part I

What this lecture covers

The lecture continues refining the deprivation account of death's badness from the previous session. It first works out the modest existence requirement in more detail, showing it avoids the absurdity of pitying never-born people while still accepting a genuinely strange consequence: shortening someone's life is worse and worse the shorter it gets, except for the final step to never existing at all, which the modest requirement treats as not bad. The lecture then turns to Lucretius's famous challenge: if nonexistence after death is bad, why isn't the symmetric nonexistence before birth equally bad? Kagan surveys several proposed answers (from Nagel, Feldman, and Parfit) without settling on one.

The second half opens the question of immortality: does accepting the deprivation account logically commit you to wanting to live forever? Kagan argues it does not, then asks the substantive question of whether immortality would actually be desirable, using Gulliver's Travels, various visions of heaven, and Bernard Williams's argument that no life could remain worth living forever. The lecture ends with an open invitation to imagine what kind of immortal life, if any, would be worth having.

Key ideas

• The modest existence requirement: something can be bad for you if you existed at some point, even if not at the time the bad thing occurs - this lets death be bad for you without requiring sympathy for never-born people.
• The shortening-life paradox: under the modest requirement, cutting a life shorter and shorter makes things worse and worse for the person, except for the final step to non-existence, which stops counting as bad at all - a genuinely odd implication.
• Lucretius's symmetry argument: nonexistence after death and nonexistence before birth are structurally alike, so if one is bad the other should be too; since nobody mourns the eternity before their birth, Lucretius concludes nonexistence after death shouldn't be mourned either.
• Loss vs. "schmoss": losing something you once had (loss) feels different from never having had something you'll get later (Kagan's coined term "schmoss"), but simply naming the asymmetry doesn't explain why loss should matter more.
• Competing explanations of the asymmetry: Nagel says imagining an earlier birth isn't really imagining yourself; Feldman says we imagine longer life extending forward but only shifting when we imagine an earlier birth; Parfit points to a general human bias toward caring about the future over the past. None fully resolves the puzzle.
• Deprivation doesn't logically require wanting immortality: death is only bad when there are more good things life would have given you; if life would eventually turn bad, dying then isn't a deprivation.
• The immortality thought experiment: even removing sickness, poverty, and other practical problems, Bernard Williams argues no single kind of life could remain desirable across an infinite stretch of time - every life would eventually become tedious or worse.

Walkthrough

The modest existence requirement in detail (0:01)

Kagan reviews last time's proposal: to avoid pitying merely-possible unborn people while still letting death be bad for the living, adopt the modest existence requirement (you must have existed at some time, though not necessarily when the bad thing occurs) rather than the bold one (you must exist at the very moment of the bad thing).

The shortening-life puzzle (4:07)

Working through a life shortened from 90 years down to 50, 20, one year, one day, one second, Kagan shows that under the modest requirement each shortening is worse than the last - until the final step, cutting the person out of existence entirely, which suddenly counts as not bad at all, since they never satisfy even the modest requirement. Kagan flags this as a genuinely counterintuitive cost of the view, without a clean fix.

Lucretius's puzzle about symmetry (8:10)

Kagan presents Lucretius's challenge: there is an infinite stretch of nonexistence before birth exactly as there is after death, yet nobody is troubled by not having existed before they were born. If that asymmetry in how we feel isn't justified, either both periods should trouble us or neither should - and Lucretius concludes neither should, undermining the fear of death.

Testing "loss" versus Nagel's and Feldman's answers (13:18)

Kagan first tries the natural response that death involves loss (having had life and losing it) while prenatal nonexistence doesn't, coining "schmoss" for the not-yet-had case, but points out this just names the asymmetry without explaining it. He then tests Nagel's proposal that an earlier birth date isn't genuinely imaginable as "you" (since a different sperm and egg would produce a different person), and refutes it using a frozen embryo thought experiment where an earlier birth really would be the same person. He then tests Feldman's proposal that imagining dying later naturally extends a life while imagining being born earlier merely shifts it, and complicates that with an asteroid scenario where an earlier birth really would mean more total life.

Parfit's asymmetry and its limits (26:43)

Kagan presents Derek Parfit's explanation: humans have a deep-seated bias toward caring more about the future than the past, illustrated by a hospital thought experiment where people prefer that a painful operation already be in their past rather than still ahead of them. Kagan accepts this as a plausible psychological explanation but questions whether it actually justifies the asymmetry as rational, leaving the puzzle open.

From deprivation to immortality: does logic require wanting to live forever? (33:57)

Kagan asks whether accepting the deprivation account logically commits you to favoring immortality, and argues it does not: death is bad only insofar as it deprives you of good things life would otherwise give you, so if a longer life would eventually turn bad (using a running analogy of being force-fed chocolate past the point of enjoyment), losing that portion of life wouldn't be a deprivation at all.

Would immortality actually be good? (39:04)

Turning to the substantive question, Kagan uses Swift's Gulliver's Travels depiction of immortals who keep aging and decaying without ever dying to show that "immortality" without health is clearly bad. He then asks students to imagine immortality with health, wealth, and every other practical problem solved, and tests whether any vision of eternal life - including religious images of heaven singing psalms forever - seems genuinely desirable, concluding with Bernard Williams's argument that no life stays worth living indefinitely, since even the best activities would eventually become tedious or unbearable.

Before you watch

• This lecture directly continues the deprivation account and existence-requirement discussion from the previous lecture; understanding the modest versus bold existence requirement is essential background.
• Familiarity with the assigned readings referenced here (Lucretius, Nagel, Feldman, Parfit, Swift's Gulliver's Travels, Montaigne, and Bernard Williams) will help follow the arguments in more depth, though the lecture explains each one.

Check your understanding

1. Explain the shortening-life puzzle: why does cutting a life shorter and shorter get worse and worse under the modest existence requirement, except for the very last step?
2. State Lucretius's symmetry argument in your own words, and explain what conclusion he draws from it about fearing death.
3. Why does Kagan think simply distinguishing "loss" from "schmoss" fails to explain why we care more about the future than the past?
4. Does accepting the deprivation account logically force you to conclude immortality would be good? Explain why or why not, using the chocolate analogy.
5. What is Bernard Williams's argument against the desirability of immortality, and what would it mean for whether death is, in principle, a bad thing?