What Professor Huxley's philosophy really proves to him is that it is true that nothing is sacred; not that it is a sacred thing to discover the truth.
We saw all this already when we were examining his comparison of the perception of moral beauty to the perception of the heat of ginger.

It is the same thing with which we are again dealing now, only we are approaching it from a slightly different point of view.

What we saw before, was that without an assent to the religious dogmas, the moral dogmas can have no logical meaning.

We have now seen that even were the two logically independent, they yet belong both of them to the same order of things; and that if our tests of truth prove the former to be illusions, they will, with precisely the same force, prove the same thing of the latter.
But the most crucial test of all we have still to come to, which will put this conclusion in a yet clearer and a more unmistakable light.

Thus far what we have seen has amounted to only this--that if science can take from man his religious faith, it leaves him a being without any moral guidance.