ABSTRACT
This chapter deals with a debate to which Ingmar Persson has made several important contributions: the question whether genetic therapy on a conceptus changes its identity, and thus may not be supported by person-affecting reasons. A person is something that develops from a conceptus. So, it might be argued, that the person-affecting view has the bizarre implication that no treatment on human beings is justified until they become persons. The chapter examines whether conceptus theory (CT) affects the identity of the person who will develop from the treated conceptus. On one view – reductionism – a person's identity over time consists in the holding of certain more particular facts, and these facts can be described in an impersonal way. On either a reductionist or a non-reductionist view of mental sense of persons, CT gives rise to potentially serious person-affecting difficulties. This is not the case with human sense of persons.
