Thus the quest for a race-mark of a mental kind is barren once more.
* * * * * What, then, you exclaim, is the outcome of this chapter of negatives?
Is it driving at the universal equality and brotherhood of man?
Or, on the contrary, does it hint at the need of a stern system of eugenics?
I offer nothing in the way of a practical suggestion.

I am merely trying to show that, considered anthropologically--that is to say, in terms of pure theory--race or breed remains something which we cannot at present isolate, though we believe it to be there.

Practice, meanwhile, must wait on theory; mere prejudices, bad as they are, are hardly worse guides to action than premature exploitations of science.
As regards the universal brotherhood of man, the most that can be said is this: The old ideas about race as something hard and fast for all time are distinctly on the decline.

Plasticity, or, in other words, the power of adaptation to environment, has to be admitted to a greater share in the moulding of mind, and even of body, than ever before.
But how plasticity is related to race we do not yet know.

It may be that use-inheritance somehow incorporates its effects in the offspring of the plastic parents.