Lecture 19: Immortality, Part II; The Value of Life, Part I

What this lecture covers

The lecture finishes the immortality discussion from the previous session. Kagan works through several attempts to imagine a life worth living forever - endlessly repeated favorite activities, pleasure-machine stimulation like a rat pressing a lever, and radical memory loss and personality change across eons - and argues each one either becomes tedious or stops being something you'd actually want for yourself. He sides with Bernard Williams: immortality would be a nightmare, though this doesn't mean dying at 50 or 80 is good, since a life can still end too soon relative to what more good it would have held.

The second half opens the topic of well-being: what makes a life good or bad for the person living it. Kagan introduces the instrumental/intrinsic value distinction, then hedonism (the view that pleasure is the only intrinsic good and pain the only intrinsic bad). He explains how hedonism lets you evaluate whole lives or individual choices by weighing pleasure against pain, then challenges the view using Robert Nozick's experience machine - a device that could give you any experience you want, indistinguishable from reality from the inside - arguing that most people would refuse permanent life on the machine, which shows pleasure alone can't be all that matters.

Key ideas

• No activity survives being done forever: repeating even a favorite pursuit (Thai food, crossword puzzles, math, art) across genuinely unlimited time becomes tedious, according to Kagan's own introspective test.
• The rat-lever thought experiment: a rat wired to self-stimulate its pleasure center will do so endlessly and happily, but a human, able to reflect on and step back from experience, would eventually be horrified by an unending cycle of simple pleasure.
• The Methuselah dilemma revisited: making an immortal "you" avoid boredom through radical memory loss and personality change produces someone so unlike you that surviving as them no longer satisfies what you actually want from survival.
• Williams's conclusion: no kind of life, however constructed, remains desirable forever - immortality would be undesirable, but this doesn't make our actual, comparatively short lives good; they can still end too soon.
• Instrumental vs. intrinsic value: most goods on an ordinary list (jobs, money, ice cream) are valuable only because of what they lead to; something is intrinsically valuable when it's worth having for its own sake.
• Hedonism: the view that pleasure is the only intrinsic good and pain the only intrinsic bad, so a life's worth is roughly the balance of pleasure over pain.
• The experience machine: Nozick's thought experiment imagining a machine that produces perfectly realistic experiences of anything you want, indistinguishable from the real thing from the inside.
• Why the experience machine refutes hedonism: most people would refuse to spend their whole life on the machine even though it maximizes pleasurable experience, showing that something besides the quality of your inner experience matters to a good life.

Walkthrough

Testing whether any repeated life is enjoyable forever (0:01)

Kagan works through examples - eating favorite food daily, doing crossword puzzles, pursuing math or philosophy, even a rich mixture of daily activities - and argues that stretched across literal eternity, each becomes stale, since forever genuinely means forever, not merely an extremely long time.

The rat-pleasure machine and why humans differ from rats (6:07)

Kagan describes real experiments where rats will press a lever to self-stimulate pleasure until they die of neglecting food and everything else. He argues that while a rat wired this way might happily continue forever, a human's capacity for reflection - stepping back to ask "is this all there is?" - would eventually turn the same endless pleasure into a horror, unless the reflective capacity itself were removed, which nobody would actually want done to them.

Boredom, memory loss, and the Methuselah problem (12:11)

As a further fix, Kagan imagines an immortal existence with progressive memory loss and radically shifting tastes and interests, so boredom never fully sets in. He connects this to the earlier discussion of Methuselah in the personal-identity unit: even if this radically transformed future being is technically "you," it may be so unlike your current self that its continued existence doesn't give you what you actually want from survival.

Concluding on immortality (18:21)

Kagan concludes he agrees with Bernard Williams that immortality would not be desirable - any life would eventually become intolerable, so dying guarantees we escape that fate. He clarifies this doesn't mean actual deaths at 50, 80, or 100 are good, since life could still have held more good things; the ideal, following Julian Barnes's imagined heaven, might be living exactly as long as you want and then being able to stop.

From immortality to the value of life (22:21)

Kagan pivots to a new topic needed to make sense of the deprivation account: what makes a life good or bad for the person living it. He introduces the distinction between instrumental value (good because of what it leads to) and intrinsic value (good in itself), using examples like jobs, money, and ice cream to trace a chain back to pleasure as an apparent intrinsic good.

Hedonism as a theory of well-being (29:34)

Kagan defines hedonism: pleasure is the only intrinsic good, pain the only intrinsic bad, so a life's overall value is (roughly) the balance of pleasure over pain, weighted for intensity and duration. This framework lets you evaluate an entire life in retrospect or compare possible futures, such as choosing between colleges or careers, by asking which path holds more net pleasure.

Refuting hedonism with the experience machine (41:01)

Kagan presents Robert Nozick's experience machine: a device producing perfectly realistic experiences of anything you choose - climbing Everest, writing a great novel, curing cancer - indistinguishable from the real thing from inside your mind. He argues that most people, asked whether they would want their whole life spent on the machine, say no, even though it maximizes pleasurable experience by hypothesis. Since hedonism should say the machine is the perfect life, this reluctance shows hedonism must be missing something about what makes a life genuinely good.

Before you watch

• This lecture directly continues the immortality discussion begun in the previous lecture, including Bernard Williams's argument and the deprivation account of death's badness.
• The Methuselah case referenced here comes from the course's earlier unit on personal identity; recalling that discussion helps with the memory-loss argument in this lecture.

Check your understanding

1. Why does Kagan think no single activity or fixed set of activities could remain enjoyable if pursued literally forever?
2. What is the crucial difference Kagan draws between a rat on a pleasure lever and a human in the same position?
3. Why doesn't solving boredom through radical memory loss and personality change give Kagan what he actually wants from immortality?
4. Explain the distinction between instrumental and intrinsic value, and where pleasure fits according to hedonism.
5. What is Nozick's experience machine, and why does most people's reluctance to live on it permanently count as an objection to hedonism?