ABSTRACT. Substrate is morally irrelevant. We differentiate morally between actual and potential beings: the latter do not exist now and will never exist unless we bring them into existence. It is generally unethical to create a person whose life is expected to be not worth living. A being's moral status is not affected by how it came into existence. Creators of new beings have a pro tanto moral reason to select to create, of the possible beings they could create, the one that is expected to have the life most worth living. Procreators have a moral responsibility to make fair provisions for their progeny. To the extent that procreators have control over what sort of being they create, they are responsible for that being's actions.