Eugenics, Experimentation, Affirmation

A revaluation of all values, on the basis of the Will to Power, might recast Eugenics, from as 'tampering with Nature', or as 'defying God', to the noble enterprise of the generating of superior beings.  However, it is unclear if that transvaluation adequately anticipates the challenge presented by what Mengele and his associates epitomize.  Now, the history of admired self-sacrifice, in the name of a higher good, evinces that what in such experiments horrifies is not necessarily their content, but the fact that participation in them is involuntary.  Correspondingly, Nietzsche seems to implicitly endorse such practices in many of his uses of the term 'slave'.  However, that implication is not necessarily inherent in the doctrine of the Will to Power, itself, which, as the promotion of maximal Power, entails maximal voluntarism, but seems to derive only from Nietzsche's articulation of it as a 'Will to Overpowering' doctrine.  So, the better defense of Eugenics, and of Experimentalism, requires the further condition of the universal affirmation of participation, a modification that is not clearly one that Nietzsche would embrace.