Modality and Counterfactuals: Understanding the Role and Context of Metaphysical Underpinnings for Harm, Benefit and Identity Claims Arising from Genome Editing and Genetic Modification.

Deriving ethical conclusions from arguments that rely heavily on metaphysical foundations, as Parfit (1984) does in generating his Nonidentity Problem, is an approach fraught with problems. Sparrow’s use of these Parfitian distinctions between “person-affecting” and “identity-affecting” interventions is just such a case in point. For, while Sparrow has very effectively highlighted some of the technical particulars of genome editing, he, like many other bioethicists, has fallen into a philosophical mire. This involves utilizing metaphysical assumptions as if they were a fixed, determinate matter in order to establish what they take to be an inescapable ethical conclusion about some new area of application. Parfit’s arguments have undoubtedly shaped attitudes in bioethics. Although Parfit’s own arguments were brilliant, original, and imaginative, they too suffer from this very problem—a failure to fully contextualize the metaphysical underpinnings—resulting in ethical conclusions of quite staggering proportions about the welfare of future generations presented as if they were inevitable and inescapable. If more bioethicists were to contextualize such theoretical underpinnings, we could avoid the constant catch-all justifications based on a re-application of them every time a new genetic or reproductive technology came around and shift to a more productive area of ethical debate about the welfare of future generations. QUESTIONABLE METAPHYSICS: THE ASSUMPTIONS UNDERPINNING PARFIT’S NONIDENTITY ARGUMENTS