"But Euclid has, demonstrated it. His demonstration has existed for two thousand years, and, during that term, has proved satisfactory to every man by whom it has been understood." I am nevertheless uninformed. The knowledge of truth lies in the perceived agreement or disagreement of the terms of a proposition. So long as I am unacquainted with the middle term by means of which they may be compared, so long as they are incommensurate to my understanding, you may have furnished me with a principle from which I may reason truly to further consequences; but, as to the principle itself, I may strictly be said to know nothing.
Every proposition has an intrinsic evidence of its own. Every consequence has premises from which it flows; and upon them, and not upon anything else, its validity depends. If you could work a miracle to prove "that the three angles of a triangle were equal to two right angles", I should still know that the proposition had been either true or false previously to the exhibition of the miracle; and that there was no necessary connection between any one of its terms and the miracle exhibited. The miracle would take off my attention from the true question to a question altogether different, that of authority. By the authority adduced I might be prevailed on to yield an irregular assent to the proposition; but I could not properly be said to perceive its truth.
But this is not all. If it were, it might perhaps be regarded as a refinement foreign to the concerns of human life. Positive institutions do not content themselves with requiring my assent to certain propositions, in consideration of the testimony by which they are enforced. This would amount to no more than advice flowing from a respectable quarter, which, after all, I might reject if it did not accord with the mature judgement of my own understanding.
But in the very nature of these institutions there is included a sanction, a motive either of punishment or reward, to induce me to obedience.
It is commonly said "that positive institutions ought to leave me free in matters of conscience, but may properly interfere with my conduct in civil concerns." But this distinction seems to have been very lightly taken up. What sort of moralist must he be, whose conscience is silent as to what passes in his intercourse with other men? Such a distinction proceeds upon the supposition "that it is of great consequence whether I bow to the east or the west; whether I call the object of my worship Jehovah or Allah; whether I pay a priest in a surplice or a black coat. These are points in which an honest man ought to be rigid and inflexible. But as to those other, whether he shall be a tyrant, a slave or a free citizen;Chapter hether he shall bind himself with multiplied oaths impossible to be performed, or be a rigid observer of truth; whether he shall swear allegiance to a king de jure, or a king de facto, to the best or the worst of all possible governments: respecting these points he may safely commit his conscience to the keeping of the civil magistrate." In reality, by as many instances as I act contrary to the unbiased dictate of my own judgement, by so much I abdicate the most valuable part of the character of man.
I am satisfied at present that a certain conduct, suppose it be a rigid attention to the confidence of private conversation, is incumbent on me.
You tell me "there are certain cases of such peculiar emergency as to supersede this rule." Perhaps I think there are not. If I admit your proposition, a wide field of enquiry is opened respecting what cases do or do not deserve to be considered as exceptions. It is little likely that we should agree respecting all these cases. How then does the law treat me for my conscientious discharge of what I conceive to be my duty? Because I will not turn informer (which, it may be, I think an infamous character) against my most valued friend, the law accuses me of misprision of treason, felony or murder, and perhaps hangs me. I believe a certain individual to be a confirmed villain and a most dangerous member of society, and feel it to be my duty to warn others, perhaps the public, against the effect of his vices. Because I publish what I know to be true, the law convicts me of libel, scandalum magnatum, and crimes of I know not what complicated denomination.
If the evil stopped here, it would be well. If I only suffered a certain calamity, suppose death, I could endure it. Death has hitherto been the common lot of men, and I expect, at some time or other, to submit to it.
Human society must, sooner or later, be deprived of its individual members, whether they be valuable, or whether they be inconsiderable. But the punishment acts, not only retrospectively upon me, but prospectively upon my contemporaries and countrymen. My neighbour entertains the same opinion respecting the conduct he ought to hold, as I did. The executioner of public justice however interposes with a powerful argument, to convince him that he has mistaken the path of abstract rectitude.