1.1 Goals 1.1.1 I have two main goals in this book. The first is to give an account of the moral significance of merely possible persons ? persons who, relative to a particular 1 circumstance, or possible future or world, could but in fact never do exist. I call that account Variabilism. My second goal is to use Variabilism to begin to address the problem of abortion. 1.1.2 We ought to do the best we can for people. And we consider this obligation to extend to people who are, relative to a world, existing or future. But does it extend to merely possible people as well? And, if it does, then does it extend to making things better for them by way of bringing them into existence? If we say that surely it doesn?t, does that then mean that our obligation to do the best we can for people does not, after all, extend to the merely possible ? that the merely p- sible do not matter morally? But if the merely possible do not matter morally, then doesn?t that mean that it would be permissible for us to bring them into miserable existences ? and even obligatory to do just that ? in the case where bringing the merely possible into miserable existences creates additional wellbeing for existing 1 References to merely possible persons and, later on, to persons who do exist ? existing persons