Now here we find ourselves confronted with an amazing fact. When, in the past, opinions so arguable have been enforced by State violence, it has been at the instigation of fanatics who held them for fixed and flaming certainties. If truths could not be evaded by their enemies, neither could they be altered even by their friends. But what are the certain truths that the secular arm must now lift the sword to enforce? Why, they are that very mass of bottomless questions and bewildered answers that we have been studying in the last chapters --- questions whose only interest is that they are trackless and mysterious; answers whose only glory is that they are tentative and new. The devotee boasted that he would never abandon the faith; and therefore he persecuted for the faith. But the doctor of science actually boasts that he will always abandon a hypothesis; and yet he persecutes for the hypothesis. The Inquisitor violently enforced his creed, because it was unchangeable. The savant enforces it violently because he may change it the next day.

Now this is a new sort of persecution; and one may be permitted to ask if it is an improvement on the old. The difference, so far as one can see at first, seems rather favourable to the old. If we are to be at the merciless mercy of man, most of us would rather be racked for a creed that existed intensely in somebody's head, rather than vivisected for a discovery that had not yet come into anyone's head, and possibly never would. A man would rather be tortured with a thumbscrew until he chose to see reason than tortured with a vivisecting knife until the vivisector chose to see reason. Yet that is the real difference between the two types of legal enforcement. If I give in to the Inquisitors, I should at least know what creed to profess. But even if I yelled out a credo when the Eugenists had me on the rack, I should not know what creed to yell. I might get an extra turn of the rack for confessing to the creed they confessed quite a week ago.

-Eugenics and Other Evils (1922)