Truth indeed is sacred; but, as Pilate said, "What is truth?" Show us the undoubted infallible criterion of absolute truth, and we will hold it as a sacred inviolable thing. But in the absence of that infallible criterion, we have all an equal right to grope about in our search of it, and no body and no school nor clique must be allowed to set up a standard of orthodoxy which shall bar the freedom of scientific inquiry.

Chapter VIII : Concluding Remarks, The Noxious Influence of Authority, p. 220. - The Theory of Political Economy (1871)