There is no 'eugenics' in Nietzsche - despite occasional references to 'breeding'- at least no more than is implicit in the recommendation to choose a partner under decent lightning conditions and with one's self-respect intact. Everything else falls under training, discipline, education and self-design - the Übermensch implies not a biological but an artistic, not to say an acrobatic programme. The only thought-provoking aspect of the marriage recommendation quoted above is the difference between onward and upward propagation. This coincides with a critique of mere repetition - obviously it will no longer suffice in future for children, as one says, to 'return' in their children. There may be a right to imperfection, but not to triviality.