And yet the positive school announce solemnly that they will not deny it.

Now why is this?
It is true that they cannot prove its non-existence; but this is no reason for professing a solemn uncertainty as to its existence.

We cannot prove that each time a cab drives down Regent Street a stick of barley-sugar is not created in Sirius.

But we do not proclaim, to the world our eternal ignorance as to whether or no this is so.

Why then should our positivists treat in this way the alleged immaterial part of consciousness?
Why this emphatic protestation on their part that there may exist a something which, as far as the needs of their science go, is superfluous, and as far as the logic of their science goes is impossible?
The answer is plain.