'The moral of my lecture tonight is twofold – there is still some hope for a philosophical theory of Darwinian evolution; and I urge that those who are rushing forward and describing epilepsy, [21-22] mental defect, insanity, to say nothing of shyness, and indolence, as ’unit characters,’ are going far beyond what the data permit: and their teaching may involve grave social consequences, when we apply it to legislation and advise on the basis of it marriage or restraint from marriage. Albinism was a ‘unit character’ not many years ago, now we are told there are 15 to 20 types of it & perhaps more. ‘Mental defect’ is a ‘unit character’ just now, there will be 15 to 20 types of it, no doubt, in a few years. I appeal for delay in judgement, and [that] the public should not accept without being cautioned, a theory of heredity, which not only reverses all philosophical Darwinism, but which does not stand the analysis of measuring rod and microscope when they are applied to it.’ (ff. 21-22)