Two ways to define MB

DeGrazia presents MB as a form of enhancement directed at moral capacities. There are, in the philosophical literature, two broad approaches to defining human enhancement. Simplifying somewhat, one account identifies enhancement with improvement. DeGrazia joins other advocates of MB in preferring this type of account, defining a human enhancement as ‘any deliberate intervention that aims to improve an existing capacity, select for a desired capacity, or create a new capacity in a human being.’1

An alternative approach relativises enhancement to human norms.2 ,3 In this view, improvements up to levels of functioning properly considered normal for humans are therapy, not enhancement. Improvements beyond those levels are enhancements. The injection of synthetic erythropoietin (EPO) by someone suffering from anaemia is therapy. When healthy Tour de France competitors inject EPO, it is enhancement.

We can minimise philosophical disputes about word meanings by endorsing a conceptual pluralism that acknowledges the need for more than one concept of human enhancement to address the hugely varied ways in which technology may alter humans. In the debate about biomedical moral improvements there would be enhancement as improvement and enhancement beyond human norms.

DeGrazia effectively deploys the concept of enhancement as improvement to …