Degrees of Certitude
The gradations of certitude and probability; how degrees of assent correspond to the strength of the evidence.
In its formal character — the exclusion of all fear of error — certitude admits no degrees: any admixture of fear of error means the assent is opinion, not certitude. But with respect to the motives on which certitude rests, three descending grades are distinguished: metaphysical certitude (absolute, unconditional — grounded in essence, admits no exception even by miracle: 'A square circle is impossible'); physical certitude (conditional on the unthwarted continuance of natural processes — Lazarus's resurrection was possible as a miracle); moral certitude (conditional on the rational and normal conduct of persons — the weakest grade, but sufficient for all ordinary practical purposes, including legal conviction and historical knowledge). Each grade fully excludes fear of error within its proper sphere.
of Certitude
Meaning of Degrees of Certitude
A “degree” or “grade” suggests a step in a series, like a rung in a ladder or a stage in a stairway. If there are degrees of certitude, this must mean that some things are more certain, some things less certain, some things most certain.
Certitude has two points about it that may be considered when we ask whether there are or can be degrees of certitude. One of these is the fact that certitude is a firm assent of the mind excluding fear of the contradictory. The other point is that certitude rests upon motive, upon evidence, and this may be investigated to see whether it admits of degrees.
Considering the first point, viz., the exclusion of fear of being wrong, we find no degrees of certitude.
For every certitude, to be certitude at all, must perfectly exclude all fear of error. This is part and parcel of the very definition of certitude.
Considering the second point, viz., the motives of certitude, we discern degrees, and we shall study them in the next paragraph.
Actual Degrees of Certitude
The assent of the mind to known truth may be regarded as subject to grades or degrees according to the character of the motives upon which the mind relies in giving its firm assent. Thus metaphysical certitude, founded as it is upon the very essences of things, is wholly absolute, knows no conditions, no “if’s” or “provided that’s.” Physical certitude rests on the regularity of nature, and depends upon the uninterrupted and unthwarted continuance of natural processes. It rests upon the condition, “provided that nature is not interfered with; provided there is no miracle.” Hence metaphysical certitude is a higher grade or degree of certitude than physical certitude, inasmuch as the absolute or unconditioned is a higher grade than the conditioned. To illustrate: my certitude that a circle is “perfectly round” is metaphysical certitude, for perfect roundness is the very essence of the circle. Thus I know that a “square circle” is impossible, that it simply cannot be, even by a miracle. My certitude that the dead and buried Lazarus will not walk again among men in earthly existence is physical certitude; it rests upon the constancy and consistency of nature and upon the condition that no miracle intervene to make an exception to that consistency. But a miracle does intervene; the condition is not fulfilled; Lazarus comes back to life. Thus physical certitude is a lesser grade of certitude than metaphysical certitude.
Again: moral certitude, while true certitude, depends upon the rational and normal conduct of men.
I am certain that a mother loves her child, even though a rare exception to this rule may occur without the intervention of a miracle. Hence moral certitude rests upon a condition that is more likely to have an exception than the condition upon which physical certitude rests; in so far, moral certitude is a lesser degree of certitude than physical certitude.
Metaphysical, physical, and moral certitude are, therefore, not only classes of certitude; they are grades or degrees of certitude. They are degrees of certitude because they rest upon motives of graded necessity for their acceptance by the mind.
In a word, there are degrees of certitude founded upon the motives which impel the mind to give its unwavering assent. But there are no degrees of certitude in the sense of degrees in the exclusion of the fear of error which characterizes the unwavering assent. If the smallest fear of error should creep in, the assent of mind would no longer be certitude, but opinion, SUMMARY or THE ARTICLE In this very short article we have studied the interesting and important matter of degrees of certitude.
We have seen that certitude admits no degrees in its exclusion of the fear of error, but does admit degrees with respect to the motives upon which it rests. The degrees of certitude in the descending scale are metaphysical, physical, and moral certitude.