Or again: I depose on my oath in a court of justice, to the best of my knowledge and belief, that I was robbed by the prisoner at the bar. Then, when the real offender is brought before me, I am obliged, to my great confusion, to retract. Because I have been mistaken in my certitude, may I not at least be certain that I have been mistaken? And further, in spite of the shock which that mistake gives me, is it impossible that the sight of the real culprit may give me so luminous a conviction that at length I have got the right man, that, were it decent towards the court, or consistent with self-respect, I may find myself prepared to swear to the identity of the second, as I have already solemnly committed myself to the identity of the first? It is manifest that the two certitudes stand each on its own basis, and the antecedent objection to the admission of a truth which was brought home to me second, drawn from a hallucination which came first, is a mere abstract argument, impotent when directed against good evidence lying in the concrete. 3. If in the criminal case which I have been supposing, the second certitude, felt by a witness, was a legitimate state of mind, so was the first. An act, viewed in itself, is not wrong, because it is done wrongly. False certitudes are faults because they are false, not because they are (so-called) certitudes. They are, or may be, the attempts and the failures of an intellect insufficiently trained, or off its guard. Assent is an act of the mind, congenial to its nature; and it, as other acts, may be made both when it ought to be made, and when it ought not. It is a free act, a personal act for which the doer is responsible, and the actual mistakes in making it, be they ever so numerous or serious, have no force whatever to prohibit the act itself. We are accustomed in such cases, to appeal to the maxim, “Usum non tollit abusus;” and it is plain that, if what may be called functional disarrangements of the intellect are to be considered fatal to the recognition of the functions themselves, then the mind has no laws whatever and no normal constitution. I just now spoke of the growth of knowledge; there is also a growth in the use of those faculties by which knowledge is acquired. The intellect admits of an education; man is a being of progress; he has to learn how to fulfil his end, and to be what facts show that he is intended to be. His mind is in the first instance in disorder, and runs wild; his faculties have their rudimental and inchoate state, and are gradually carried on by practice and experience to their perfection. No instances then whatever of mistaken certitude are sufficient to constitute a proof, that certitude itself is a perversion or extravagance of his nature.