Whence did we get the habit of requiring proofs of each idea that is expressed? If we put aside the consideration, as having no real meaning in the present case, that men do often purposely deceive their neighbours for gain or other interests, then strictly speaking the necessity for proof is entirely removed. It is true that we can still deceive ourselves and fall into involuntary error. Sometimes we take a vision for a reality, and we wish to guard against that offensive mistake. But as soon as the possibility of _bona fide_ error is removed, then we may relate simply without arguments, judgments, or references. If you please, believe; if you don't, don't. And there is one province, the very province which has always attracted to itself the most remarkable representatives of the human race, where proofs in the general acceptation are even quite impossible. We have been hitherto taught that that which cannot be proved, should not be spoken about. Still worse, we have so arranged our language that, strictly speaking, everything we say is expressed in the form of a judgment, that is, in a form which presupposes not merely the possibility but the necessity of proofs. Perhaps this is the reason why metaphysics has been the object of incessant attack. Metaphysics evidently was not only unable to find a form of expression for her truths which would free her from the obligation of proof; she did not even want to. She considered herself the science _par excellence,_ and therefore supposed that she had more largely and more strictly to prove the judgments which she took under her wing. She thought that if she were to neglect the duty of demonstration she would lose all her rights. And that, I imagine, was her fatal mistake. The correspondence of rights and duties is perhaps a cardinal truth (or a cardinal fiction) of the doctrine of law, but it has been introduced into the sphere of philosophy by a misunderstanding. Here, rather, the contrary principle is enthroned: rights are in inverse proportion to duties. And only there where all duties have ceased is the greatest and most sovereign right acquired--the right of communion with ultimate truths. Here we must not for one moment forget that ultimate truths have nothing in common with middle truths, the logical construction of which we have so diligently studied for the last two thousand years. The fundamental difference is that the ultimate truths are absolutely unintelligible. Unintelligible, I repeat, but not inaccessible. It is true that middle truths also are, strictly speaking, unintelligible. Who will assert that he understands light, heat, pain, pride, joy, degradation?