That there are cases, in which evidence, not sufficient for a scientific proof, is nevertheless sufficient for assent and certitude, is the doctrine of Locke, as of most men. He tells us that belief, grounded on sufficient probabilities, “rises to assurance;” and as to the question of sufficiency, that where propositions “border near on certainty,” then “we assent to them as firmly as if they were infallibly demonstrated.” The only question is, what these propositions are: this he does not tell us, but he seems to think that they are few in number, and will be without any trouble recognized at once by common-sense; whereas, unless I am mistaken, they are to be found throughout the range of concrete matter, and that supra-logical judgment, which is the warrant for our certitude about them, is not mere common-sense, but the true healthy action of our ratiocinative powers, an action more subtle and more comprehensive than the mere appreciation of a syllogistic argument. It is often called the “judicium prudentis viri,” a standard of certitude which holds good in all concrete matter, not only in those cases of practice and duty, in which we are more familiar with it, but in questions of truth and falsehood generally, or in what are called “speculative” questions, and that, not indeed to the exclusion, but as the supplement of logic. Thus a proof, except in abstract demonstration, has always in it, more or less, an element of the personal, because “prudence” is not a constituent part of our nature, but a personal endowment. And the language in common use, when concrete conclusions are in question, implies the presence of this personal element in the proof of them. We are considered to feel, rather than to see, its cogency; and we decide, not that the conclusion must be, but that it cannot be otherwise. We say, that we do not see our way to doubt it, that it is impossible to doubt, that we are bound to believe it, that we should be idiots, if we did not believe. We never should say, in abstract science, that we could not escape the conclusion that 25 was a mean proportional between 5 and 125; or that a man had no right to say that a tangent to a circle at the extremity of the radius makes an acute angle with it. Yet, though our certitude of the fact is quite as clear, we should not think it unnatural to say that the insularity of Great Britain is as good as demonstrated, or that none but a fool expects never to die. Phrases indeed such as these are sometimes used to express a shade of doubt, but it is enough for my purpose if they are also used when doubt is altogether absent. What, then, they signify, is, what I have so much insisted on, that we have arrived at these conclusions—not _ex opere operato_, by a scientific necessity independent of ourselves,—but by the action of our own minds, by our own individual perception of the truth in question, under a sense of duty to those conclusions and with an intellectual conscientiousness.