There is much reason, we think, to regret the existence of such a wide difference between the philosophical and the popular sense of an expression, which must occur so often both in speculative discussion and in the intercourse of common life.

It may be doubted whether the metaphysician is entitled to borrow the language of society, and to engraft upon it an arbitrary definition of his own, different from and even inconsistent with that which it bears in common usage.

Nor can he plead necessity as a sufficient excuse, or the accuracy of his definition as an effectual safeguard, since, however needful it may be to discriminate between _different species_ of Certitude, by marking their peculiar characteristics and respective sources, surely this might be done more safely and satisfactorily by designating one kind of it as Intuitive, another as Demonstrative, another as Moral, or Experimental, or Historical, than it can be by any arbitrary restriction of the _generic_ term to one or two of the many species which are comprehended under it.
No doubt there is a real distinction, and one of great practical importance, between _certitude_ and _probability_; but this distinction is not overlooked in the language of common life;--it is only necessary to determine what truths belong respectively to each: whereas when all the truths of Experience, and even, in some cases, those of scientific Induction, are ranked under the head of _probability_ merely, is it not evident that the language of Philosophy is in this respect at variance with the prevailing sense of mankind?
An attempt has sometimes been made to draw a distinction between _popular_ and _philosophical_ Certitude, or, in other words, between the unreflecting belief of the many and the scientific belief of the few.
Thus, M.Franck distinguishes Certitude, first of all, from the blind faith which commences with the earliest dawn of intelligence: then, from the doubt which supervenes on the initial process of inquiry; and then, from that half-knowledge, that middle term between doubt and certainty, which is called _probability_.

And M.Javari speaks of Certitude "as the complete demonstration, acquired by reflection, of the legitimacy of any judgment, or of the reality of any object: this is definitive and scientific certitude, which is contrasted with that belief, however strong, which springs, not from the _reflective_, but the _direct and spontaneous_ exercise of our faculties."[235] It must be evident that, according to this definition of the term, Certitude, in the scientific sense of it, as the product of philosophical reflection, must be the privilege and prerogative of the few, who have been led by taste or education to cultivate the study of Psychology; while the vast majority of men, who are nevertheless as _certain_ of the truths which they believe, and, to say the very least, as little liable to doubt or skepticism, as any class of philosophers whatever, must be held to have no Certitude, just because they have no Science.

It seems to be assumed that Certitude is the creation of Science, the product of reflective thought; whereas it may be demonstrably shown that without Certitude, Science would be impossible, and that reflection can give forth nothing but what it finds previously existing in the storehouse of human consciousness.