The argument of such a system must, when attentively examined, be the most untenable that can be imagined. It undertakes to prove that we must not be governed by reason. To prove! How prove? Necessarily, from the resources of reason. What can be more contradictory? If I must not trust the conclusions of reason relative to the intrinsic value of things, why trust to your reasons in favour of the benefit of being deceived? You cut up your own argument by the roots. If I must reject the dictates of reason in one point, there can be no possible cause why I should adopt them in another. Moral reasons and inducements, as we have repeatedly shown, consist singly in this, an estimate of consequences. What can supersede this estimate? Not an opposite estimate; for, by the nature of morality, the purpose, in the first instance, is to take into account all the consequences. Not something else, for a consideration of consequences is the only thing with which morality and practical wisdom are directly concerned. The moment I dismiss the information of my own eyes and my own understanding, there is, in all justice, an end to persuasion, expostulation or conviction. There is no presence by which I can disallow the authority of inference and deduction in one instance that will not justify a similar proceeding in every other.
He that, in any case, designedly surrenders the use of his own understanding is condemned to remain for ever at the beck of contingence and caprice, and is even bound in consistency no more to frame his course by the results of demonstration than by the wildest dreams of delirium and insanity.