Update (13 August, 2007). I’ve now written a very short paper on this issue: How to Live a Life Worth Living. As you’ll see, it was significantly influenced by useful comments I received here.
The recent discussion of McTaggart initiated by Kris has been very interesting. Among other things, it has got me thinking about the notion of “a life worth living”. Although ubiquitous in population ethics, this notion resists easy analysis. One wants to say that a life is worth living just in case it would be better to live it rather than live no life at all. But on reflection, that seems mysterious. How does one live no life at all? It seems like one of the relata of the “better than” relation has gone missing. We’re trying to compare something, a life, with nothing.
Here I shall propose an analysis that avoids such mysterious comparisons. On my proposal, whether a life is worth living depends solely on whether it is better than certain other lives.
Instead of giving an elaborate explanation of the analysis, I’m just going to state it very austerely. I hope that’ll be enough to get the discussion rolling.
Let L be a possible life, a life lived by someone in some possible world. Assume that L is composed of temporal parts, which obey classical mereology. In particular, for any parts of L, there is a part of L that is a fusion of those parts. Assume that some parts of L are simple, i.e. they have no parts. Call these slices of L. Assume that the slices of L are ordered by an “earlier than” relation.
Say that F is a future of L iff F is a proper part of L and no slice of F is earlier than any slice of L that is not a slice of F. Assume that for any future F of L there is a unique possible life L-F such that L-F is an intrinsic duplicate of the largest part of L that doesn’t overlap F, i.e. the mereological complement or remainder of F in L.
Now here’s the view:
- A future F of a life L is worth living iff L is better than L-F.
- A life L is worth living iff some future F of L is such that every future of which F is a part is worth living.