GKC on the New Theologians

Nancy at Flying Stars referred (in a comment I have since lost the reference) to GKC's point about proving the existence of sin. I am happy to provide the context:

Modern masters of science are much impressed with the need of beginning all inquiry with a fact. The ancient masters of religion were quite equally impressed with that necessity. They began with the fact of sin - a fact as practical as potatoes. Whether or no man could be washed in miraculous waters, there was no doubt at any rate that he wanted washing. But certain religious leaders in London, not mere materialists, have begun in our day not to deny the highly disputable water, but to deny the indisputable dirt. Certain new theologians dispute original sin, which is the only part of Christian theology which can really be proved. Some followers of the Reverend R. J. Campbell, in their almost too fastidious spirituality, admit divine sinlessness, which they cannot see even in their dreams. But they essentially deny human sin, which they can see in the street. The strongest saints and the strongest sceptics alike took positive evil as the starting-point of their argument. If it be true (as it certainly is) that a man can feel exquisite happiness in skinning a cat, then the religious philosopher can only draw one of two deductions. He must either deny the existence of God, as all atheists do; or he must deny the present union between God and man, as all Christians do. The new theologians seem to think it a highly rationalistic solution to deny the cat.
[GKC, Orthodoxy CW1:217, emphasis added]

Hence it appears that Nancy's antagonist is a "new" theologian, by GKC's view. Odd that GKC wrote this book in 1908.