Him--that He _cannot_ reveal Himself to man[39]. _Pure_ agnosticism is
as defined by Huxley.

Of all the many scientific men whom I have known, the most pure in his
agnosticism--not only in profession but in spirit and conduct--was
Darwin. (What he says in his autobiography about Christianity[40] shows
no profundity of thought in the direction of philosophy or religion. His
mind was too purely inductive for this. But, on this very account, it is
the more remarkable that his rejection of Christianity was due, not to
any _a priori_ bias against the creed on grounds of reason as absurd,
but solely on the ground of an apparent moral objection _a
posteriori_[41].) Faraday and many other first-rate originators in
science were like Darwin.

As an illustration of impure agnosticism take Hume's _a priori_ argument
against miracles, leading on to the analogous case of the attitude of
scientific men towards modern spiritualism. Notwithstanding that they
have the close analogy of mesmerism as an object-lesson to warn them,
scientific men as a class are here quite as dogmatic as the straightest
sect of theologians. I may give examples which can cause no offence,
inasmuch as the men in question have themselves made the facts public,
viz. ---- refusing to go to [a famous spiritualist]; ---- refusing to
try ---- in thought-reading[42]. These men all _professed_ to be
agnostics at the very time when thus so egregiously violating their
philosophy by their conduct.

Of course I do not mean to say that, even to a pure agnostic, reason
should not be guided in part by antecedent presumption--e.g. in ordinary
life, the _prima facie_ case, motive, &c., counts for evidence in a
court of law--and where there is a strong antecedent improbability a