Buchanan and the conservative argument against human enhancement from biological and social harmony

In his recent Beyond Humanity? (2011), Allen Buchanan takes issue with a slew of arguments against human enhancement put forward by prominent conservatives. This chapter discusses his treatment of the conservative line of argument against human enhancement ‘from biological and social harmony’ (Buchanan 2011, pp. 161–2). It identifies a version of this line of argument that has more going for it than Buchanan allows. It does not argue that it is strong enough to warrant the banning of the use of all human enhancement technologies, as many conservatives (and some liberals) urge, but argues that it gives us reason to be cautious about the widespread adoption of some possible human enhancements. The chapter also shows that there is nothing distinctively conservative about this line of argument. It deserves to be taken seriously by both liberals and conservatives.