detain the degeneration of the race
This is interesting in that it seems pretty defeatist. The "race" will degenerate, but we can at least slow it down! I wonder if there's a sense in which "soft" eugenicists, in addition to blaming different factors and using different methods to combat them, are also "soft" in their aspirations. This is dramatically different from the "hard" eugenicists but also reform eugenicists--who did take environment into account--who were intent on creating supermen.