water out of an empty jug

My husband paraphrased the last sentence of this Chesterton quote (the emphasis in the quote is mine) and I went and looked it up in GKC's book about Thomas Aquinas:

Suffice it to say that the mere modern evolutionists, who would ignore the argument do not do so because they have discovered any flaw in the argument; for they have never discovered the argument itself. They do so because they are too shallow to see the flaw in their own argument for the weakness of their thesis is covered by fashionable phraseology, as the strength of the old thesis is covered by old-fashioned phraseology. But for those who really think, there is always something really unthinkable about the whole evolutionary cosmos, as they conceive it; because it is something coming out of nothing; an ever-increasing flood of water pouring out of an empty jug. Those who can simply accept that, without even seeing the difficulty, are not likely to go so deep as Aquinas and see the solution of his difficulty. In a word, the world does not explain itself, and cannot do so merely by continuing to expand itself.

But anyhow it is absurd for the Evolutionist to complain that it is unthinkable for an admittedly unthinkable God to make everything out of nothing and then pretend that it is more thinkable that nothing should turn itself into everything.