Andreas Mogensen, a Senior Research Fellow at the Global Priorities Institute, has just published a draft of a paper on "Maximal Cluelessness". Abstract:
I argue that many of the priority rankings that have been proposed by effective altruists seem to be in tension with apparently reasonable assumptions about the rational pursuit of our aims in the face of uncertainty. The particular issue on which I focus arises from recognition of the overwhelming importance and inscrutability of the indirect effects of our actions, conjoined with the plausibility of a permissive decision principle governing cases of deep uncertainty, known as the maximality rule. I conclude that we lack a compelling decision theory that is consistent with a long-termist perspective and does not downplay the depth of our uncertainty while supporting orthodox effective altruist conclusions about cause prioritization.
I think this is precisely what I'm inclined to dispute. I think I simply have a preference against premature death, and that this preference doesn't rest on any belief about my long-run wellbeing. I think my long-run wellbeing is way too weird (in the sense that I'm doing things like hyperbolic discounting anyway) and uncertain to ground such preferences.
Maybe this points to a crux here: I think on sufficiently demanding notions of rationality, I'd agree with you that considerations analogous to cluelessness threaten the claim that smoking is irrational. My impression is that perhaps the key difference between our views is that I'm less troubled by this.
I'm inclined to agree. Just to clarify though, I wasn't referring to Parfit's claims about identity, which if I remember correctly are in the second or third part of Reasons and Persons. I was referring to the first part, where he among other things discusses what he calls the "self-interest theory S" (or something like this).