We may say that there must be one all-pervading soul, not because we can form any conception whatsoever of the true nature of such a soul, but because the alternative hypothesis of many individual souls is utterly obnoxious to our reason.
To those who urge that it is idle to reason about what we cannot conceive, it is sufficient answer to say that man cannot help it.
The scientist and the materialist in the ardent pursuit of knowledge soon experience the necessity of indulging in assumptions concerning force and matter, the hypothetical ether and molecules, atoms and vortices, which are as purely metaphysical as any assumptions concerning the soul.

The distinction between the realist and the idealist is a matter of temperament.

All that separated Huxley from Gladstone was a word; each argued from the unknowable, but disputed over the name and attributes of the inconceivable.

Huxley said he did not know, which was equivalent to the dogmatic assertion that he did; Gladstone said he did know, which was a confession of ignorance denser than that of agnosticism.
Those men who try not to think or reason concerning the infinite simply imprison themselves within the four walls of the cell they construct.

It is better to think and be wrong than not to think at all.