Diachronic Liberty
Why Odysseus cannot stop the disco
1. Siren Song
Philosophy pop quiz! Which of the following mythological characters is done wrong?
Odysseus the Tactician: Odysseus’ ship will soon face the Sirens, whose song is so intoxicating it will make him desire nothing more than to jump ship and swim to them, even if it kills him. Knowing this, Odysseus instructs his men to tie him to the mast so that he cannot escape. Predictably, when the ship passes by the Sirens, Odysseus screams and wails and begs to be set free. He desires it more than anything. Once out of earshot, he returns to normal, thinks of the long life ahead of him, and is devoutly thankful that his men tied him to the mast.
Orpheus the Changed: Orpheus is a great artist, and strongly believes it would be wonderful to die in an ecstatic musical passion. He does not tie himself to the mast, but sails on looking forward to his encounter with the Sirens. His men believe this is a foolish idea and that he will regret this. They overpower him and tie him to the mast. This time, too, when the ship passes by the Sirens, Orpheus screams and wails and begs to be set free. Once the song is over, he thinks of the life ahead of him and realizes how foolish he used to be for wishing to die prematurely. He is devoutly thankful that his men tied him to the mast.
Pygmalion the Idealist: Just like Orpheus the Changed, except… unchanged. When the song is over, he is still just as dedicated to his aesthetic ideals and is absolutely furious with his men for tying him up. He arrives back home, and not long after the Sirens are slain by an upstart demigod. Pygmalion lives the rest of his life regretting the lost opportunity and he never forgives his men.
I think Pygmalion’s men definitely do him wrong. He has a stable, consistent preference for risking his life for aesthetic value, even when he is removed from the possibility and is able to rationally deliberate. The aesthetic ecstasy of sacrificing everything for the Sirens would bring him even more pleasure than a bitter and unfulfilled life in his homeland. It’s hard to favor restraining Pygmalion as a consequentialist;1 deontologists may believe suicidal acts are always wrong, but are less likely to believe it is justified to deprive another person of freedom.
Orpheus is trickier, at least if his men have good reason to think he’ll change his mind after he actually hears the sirens. If so, this is textbook paternalism—overriding someone’s choice for their own good. Orpheus’ freedom is definitely violated, but it may or may not seem justified to you on paternalistic grounds. It is definitely wrong on J.S. Mill’s harm principle:
[T]he only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others. His own good, either physical or moral, is not a sufficient warrant. (emphasis mine)2
But Odysseus seems definitely in the clear. He made the decision to tie himself to the mast, and it was prudent for him to do so. Right?
Objection: Odysseus wanted his men to tie him to the mast beforehand, and afterwards he is grateful that they did it. But in between, there is a period where Odysseus is horrified that he is tied up and tries his hardest to escape, where he wishes more than anything that his men had not tied him up. Hasn’t he been coerced into staying put?
Response: Odysseus made a voluntary pact with his men to tie him up and keep him from the Sirens in the future. That decision was freely made at the time. It does not matter if later he no longer wishes he had made the decision—it was still his free choice.
This makes sense if Odysseus at time 1 (Odysseust1), before the Sirens, is the same person as Odysseus at time 2 (Odysseust2), hearing the Siren song. Presumably Odysseus’ freedom would be violated if someone else made the decision to tie him up. But what if he isn’t the same person? What if personal identity does not persist between t1 and t2?
2. Identity Skepticism
Derek Parfit is famous for (among many things!) thought experiments like this:
Here on Earth, I enter the Teletransporter. When I press some button, a machine destroys my body, while recording the exact states of all my cells. The information is sent by radio to Mars, where another machine makes, out of organic materials, a perfect copy of my body. The person who wakes up on Mars seems to remember living my life up to the moment when I pressed the button, and he is in every other way like me.3
So: is that person you, or not?
If so, what happens if there is a 2-second delay between your clone-recreation and your original body destruction, so that for two seconds there are two of you at once? Which one is you? What if the new copy used Greta Garbo’s body scan in addition to yours, such that the new you was 0.1% Garbo? What about 1%? 10%? 49.9999%?
If not, what happens as your cells grow old and die and are replaced by new cells? If 1% of all your cells are replaced, surely that doesn’t kill you. But if 100% does, then what about 10%? 20%? 49.9999%? At what point do you stop being you?
By this kind of reasoning, Parfit argues that there is no determinate answer in all cases to whether a person would be you or not. He is a reductionist about identity: a person just consists in their physical and mental states, and there is no real unanswered question “but would it be you?” other than a complete physical and mental description of the people who exist before and after the experience.4 I heartily recommend “The Unimportance of Identity” to the curious—fantastic stuff, and very readable.
Suppose Parfit is right about this. Then Odysseus and his men have a problem. It is no longer certaing whether Odysseust1 is the same person as Odysseust2. Odysseust2 is quite psychologically different from Odysseust1. His values change significantly: he only cares about the Sirens’ music. His personality might change. Clearly there is a great change in his voluntary will. If they are not the same person, then what right does Odysseust1 have to restrain Odysseust2?
Parfit writes:
[G]reat imprudence is morally wrong. We ought not to do to our future selves what it would be wrong to do to other people.5
But it would be wrong for Odysseust1 to order that Pygmalion be tied up, and Odysseust2 is a lot closer to Pygmalion than Odysseust1. So isn’t it wrong to tie himself up?
3. Arguments
Objection: Odysseust2 is more like Orpheus, in that he will eventually change his mind and be grateful that he was tied up once the Sirens are gone. Therefore Odysseust1 is merely acting paternalistically, like Orpheus’ men did.
Response: Once the Sirens are gone, Odysseust2 will once again undergo a wrenching change in psychology to a similar state to Odysseust1. If the t1 → t2 change is enough to make Odysseus a different person, then the reverse would also be true. Thus, after the Sirens are gone there is a third person, Odysseust3, who is very glad that Odysseust2 was tied up. But it is never the case that Odysseust2 is grateful or willing, and restraint goes against all his preferences. Also notice that paternalism is still an infringement of freedom, even if it’s better than not infringing on freedom, so this argument would still concede that Odysseust2 is not free.
Objection: It would be paternalistic for Odysseust1 to tie up Odysseust2. But he doesn’t do that—he ties up himself, Odysseust1. That was a free and voluntary action, and his right to take, even if the consequence is that Odysseust2 will be tied up in the future.
Response: Odysseust1 ties himself up for the sole purpose of restraining Odysseust2. If the Sirens magically untie any ropes of anyone who hears their song, he would not tie himself up. If he could press a button that would make sure that Odysseust2 were tied up while leaving his own hands free for the moment, he would press it. Saying Odysseust1 has the right to tie himself up even if it will lead to another person being restrained is rather like saying Odysseust1 has the right to rig a time bomb to his chest and walk into a crowd, even if it will result in another person being exploded. After all, it’s his bomb, and his chest! Even hardcore libertarians don’t believe in that.
Objection: Odysseust2 desires a course of action that will prevent Odysseust3 from ever coming into existence and living a happy life. Odysseust3 would not want this. If Odysseust1 does not have a right to take actions that would go against the wishes of Odysseust2, then Odysseust2 does not have the right to take actions that would go against the wishes of Odysseust3. Therefore Odysseust2 does not have a right to throw himself at the Sirens, and can be permissibly restrained for attempting to do such a thing.
Response: If Odysseust2 dies to the Sirens, Odysseust3 will never exist to begin with. There will be no person who suffers at Odysseus’t2 hands. This sounds an awful lot like Odysseust2 has a moral obligation to bring more happy people into the world, even if it runs directly counter to his own wishes for how to live his life. In that case, it would be permissible to forcibly prevent Odysseus from getting a vasectomy, even if all his past and future selves desired it, because he would be taking actions that prevent happy people from existing.6 Note that this is different than merely saying it would be better if Odysseus did create more happy future people—it is saying that it is justified to coerce him into doing so.
Objection: Okay, Odysseus is being paternalistic to his future self. However, paternalism is totally acceptable in cases where someone would suffer great harm from their choices, like death.
Response: First, we permit many people to engage in dangerous activities that are greatly meaningful to them, such as rock climbing and cave diving, and we also permit people who are suffering from a long and painful terminal illness to request that they not be resuscitated. The right to die on your own terms seems like an important freedom. Second, imagine it’s the 1970s and the Sirens don’t kill, but instead play very loud disco music that makes wayward sailors boogie. Odysseus hates disco with a burning passion and dreads the thought of dancing to it. Odysseust2, naturally, will feel very differently about disco and boogie enthusiastically. I don’t think disco dancing constitutes “great harm” comparable to death or grievous trauma. Does this mean that Odysseust1 does not have the right to tie himself to the mast? Must he surrender his future self to the Saturday night fever?7
4. My Thoughts
A more promising objection is a scalar response—there are different degrees to which Odysseust1 and Odysseust2 can be related, and the more strongly they are related, the less of an infringement it is for Odysseust1 to tie himself to the mast. This is closer to the how the substack consequentialists tend to think about “right” and “wrong” as more descriptive terms about what you have strong reasons to do or avoid, rather than fundamental boundaries or primitives.8
Or one can accept this as a consequence of Parfit’s reductionism about personal identity, and treat this as a modus tollens. I am skeptical about ethical MT based on intuition—as in my insect post, I refer folks to Silas Abrahamsen. (However, if you already think that Parfit’s reductionism is likely to be false, then it shouldn’t be that surprising to you that you can derive ridiculous-seeming consequences from it.)
I keep feeling like I could resolve this via some kind of clever Florence Bacus-style decision that I will respect the choices of my past self. I certainly appreciate the value of precommitments in my own life, and am almost always grateful for them even when they are a pain. However, there is always some transformation I could undergo that would make me, even temporarily, no longer feel that way. And that feels like such a violation of my will that I would really like precommitment mechanisms to make sure I can’t back out. But if future-Jack is really a different person, do I have the right to control him?
Unless one favors what Parfit calls an “Objective List Theory” of self-interest, in which “certain things are good or bad for us, even if we would not want to have the good things or avoid the bad things.” I personally find objective lists hard to justify—and if there were an objective list, I would expect personal freedom to be on it. Parfit, Derek. Reasons and Persons. Oxford Paperbacks. Oxford [Oxfordshire]: Clarendon Press, 1984. https://doi.org/10.1093/019824908X.001.0001.
Mill, John Stuart. On Liberty, 2011. https://www.gutenberg.org/ebooks/34901.
Parfit, Derek. “The Unimportance of Identity,” 1997. https://philpapers.org/rec/PARTUO.
He does not, however, deny that persons exist. A statue just consists in a particular arrangement of bronze, but that does not mean statues don’t exist. A nation just consists in a particular historical arrangement of people, but that does not mean nations don’t exist. Parfit, “The Unimportance of Identity.”
Parfit, Reasons and Persons, ch 14.
Since I don’t believe the ancient Greeks had condoms, and their mythological heroes were not exactly famed for their sexual restraint, the lack of a vasectomy would probably not deter Odysseus from having sex. Thus, as long as Odysseus and his wife were fertile, a vasectomy would be necessary and sufficient to prevent more children that would otherwise be born. (I know the ancient Greeks didn’t have vasectomies either.)
“Ah, but dancing to the disco now would upset Odysseus't2 future self. Fine—say there’s a storm up ahead and Odysseus knows he’s going to die anyways before he’s out of earshot of the Sirens. But he would rather not die boogie-ing. Does Odysseust1 have a right to tie himself to the mast now?
Bulldog, Bentham’s. “Right and Rich.” Substack newsletter. Bentham’s Newsletter (blog), April 13, 2025, https://benthams.substack.com/p/right-and-rich. Chappell, Richard Y. “Deontic Pluralism.” Substack newsletter. Good Thoughts (blog), March 29, 2025, https://goodthoughts.blog.