which might be given for founding the argument from analogy on the constancy of the laws of nature, and on the relation between certain physical causes and determinate effects; but their assent is required and given.
324. In all the cases cited, excepting, perhaps, that of immediate evidence, the inclination to assent may be, and really is, called common sense. The reason of this exception is, that in this case, although there is no demonstration, the predicate is nevertheless most clearly seen contained in the idea of the subject; but in the other cases there is neither demonstration nor this vision. Man assents by a natural impulse; and if any thing is objected to his belief, he does not call attention to his conception, as in immediate evidence, but is completely disconcerted, and knows not what to answer; he then applies to the objection, not the name of error, nor of absurdity, but that of extravagance, of something contrary to common sense.
Suppose, for example, a little grain of sand to be mixed with a great heap, and some one to come and say: I will put my hand into the heap, and instantly draw out the one grain hidden there. What will you object to such a one? What will the beholders reply? Nothing; or, looking at each other in perfect surprise, they will exclaim: "What extravagance! He has no common sense!" Or suppose some one to say, that all we see is nothing, that there is no external world, that we have no body, or that all told us of the existence of a city called London is untrue. Whoever hears such madness, knows not what to answer; but he repels it by a natural impulse, and the mind feels that this is nonsense without stopping to examine.
325. We shall now inquire whether common sense be a certain criterion of truth, whether it be so in all, or in what cases, and what characters it must have in order to be an infallible criterion.
Man cannot lay aside his nature: when it speaks, reason will not allow it to be ignored. A natural inclination, simply because it is natural, is in the eyes of philosophy something highly respectable: it is the province of reason and free will not to allow it to go astray. What is natural to man is not always so perfectly fixed as it is in brutes, where instinct is blind as it must be, where there is neither reason nor free will. The exercise of man's natural inclinations is subordinate to his reason and free will, and, consequently, when these are called instincts, the word has a very different meaning from what it has when applied to brutes. What happens in the moral order is also verified in the intellectual. We have not only our heart to watch, but also our understanding; both are subject to the law of perfectibility; the objects which they offer to us are good and evil, truth and error. Nature herself shows us which one we ought to choose, but does not force our choice; life and death are before us, we may select the one we please.
326. There is in man, independently of the action of free will, a quality which oftentimes has the effect of turning his natural inclinations from their object; it is weakness. Hence, it is nothing extraordinary for these inclinations to be so distorted as to lead to error instead of truth, and this renders it necessary to determine what characters common sense should have, in order to be an absolutely infallible criterion.
327. We will point out the conditions, such as we conceive them to be, of true and never-erring common sense.
First Condition.—That the inclination be every way irresistible, so that one cannot, even by the aid of reflection, resist or avoid it.
Second Condition.—That every truth of common sense be absolutely certain to the whole human race. This condition follows from the first.
Third Condition.—That every truth of common sense stand the test of reason.
Fourth Condition.—That every truth of common sense have for its object the satisfaction of some great necessity of sensitive, intellectual, or moral life.
328. When possessed of all these characters, the criterion of common sense is absolutely infallible, and may defy skeptics to assign a case wherein it has failed. The higher the degree in which the conditions are satisfied, the more certain will the criterion be. We will explain this by a few examples.
There is no doubt that ordinary men make their sensations so far objective as to transfer what passes within themselves to the exterior, without distinguishing between the subjective and the objective. Thus, when they consider colors to be in things themselves, they do not take the green, for example, to be the sensation of the green, but a thing certain, a quality, or whatever else it may be called, inherent in the object. But in reality this certainly is not so. The cause of the sensation is in the external object; such a disposition of facts also as to produce through the medium of light the impression called green. Common sense here deceives; for philosophical analysis convicts it of error. But here common sense has not the requisite conditions. In the first place, it ought to stand the test of reason; so soon as we reflect upon the case, we discover an illusion as fair as innocent. Moreover, it is not irresistible, for our assent is withheld the instant we are convinced of the illusion. Neither is the assent universal, for not all philosophers have it. Nor is it indispensable to the satisfaction of some great necessity of life. It therefore has no one of the conditions just laid down. What we have said of sight is applicable to the other senses. What is the value of the testimony of common sense inasmuch as it leads us to make sensations objective? We will answer this question.
A certainty that sensations correspond to external objects is necessary to the wants of life. Upon this all men without exception are agreed. Reflection cannot despoil us of our natural inclination; and although reason, when most it cavils, may shake the foundations of this belief, it never succeeds in convicting it of error. Even they who give the most weight to such cavils, cannot prove that bodies do not exist: they can only say that we do not know that they exist.
The natural inclination then possesses upon this point all the characteristics necessary to elevate it to the rank of an infallible criterion: it is irresistible, universal, satisfies a great necessity of life, and stands the test of reason.
As to qualities, the direct objects of sensation, it is not necessary for us that they exist in bodies themselves; it is enough that these bodies have something which produces in us, in some way or other, a corresponding impression. It is of little moment whether a green, or orange color be, or be not, a quality of objects, so long as they have some quality which produces in us the sensation of green, or orange color, as the case may be. The ordinary wants of life are not at all affected by this question; and man's relations with the sensible world would not be disturbed by the generalization of philosophical analysis. There is, perhaps, a kind of disenchantment of nature, since, despoiled of sensations, it is not nearly so beautiful; but the enchantment still continues with most men; and philosophy itself, except in brief moments of reflection, is subject to it; and even in these moments it experiences an enchantment of a different kind, as it considers how much of the beauty attributed to objects, belong to man in his own right, and that the simple exercise of a sensible being's harmonious faculties suffices to make the whole universe glow with splendor and glory.(28)
CHAPTER XXXIII.
ERROR OF LAMENNAIS ON COMMON CONSENT.
329. The instinctive faith in human authority, of which we have just treated, is a fact attested by experience, and one which no philosopher has presumed to call in doubt. This faith, duly directed by reason, constitutes one criterion of truth. The errors to which it may sometimes lead are inherent in human weakness, and are amply compensated for by the advantages derived from it by society and individuals.
A celebrated writer undertook to include all criteria in that of human authority, resolutely affirming "common consent, sensus communis, to be to us the only seal of truth."[33] His system, as strange as erroneous, in which words
