Design constraints for the post-human future

A variety of objections to human germ-line genetic engineering have been raised, such as the claim that we ought not to place individuals at significant risk without their consent. It has also been argued that it is paternalistically objectionable to confer significant benefits on individuals without their consent. As well as imposing risk of harm to non-consenting parties, there is the risk of harm to others. This paper evaluates these and related objections to germ-line genetic engineering. While a complete prohibition on human germ-line genetic engineering is rejected it is argued that acceptable germ-line engineering (a) should at least expand and enrich rather than restrict and constrain the choices for individuals affected, and (b) should not seek to change basic human dispositions and values ('human nature').