Essays in Rationalism

by Charles Robert Newman

In regard to the first of these tests, the literature of all sects and parties has been accustomed to assert that, both in matters of science and of worldly business, reason is the judge of all truth whatever, without exception.

Locke, on the other hand, informs us that reason is the judge of demonstrative truth, of logical truth, of casuistical truth, and of lawyers’ truth, and of these kinds of truth alone, but is not the judge of intuitive or self-evident truth. Our writers would tell us that to deny “what is, is” to be a true statement, would be an offence against reason; but we learn from Locke that reason has no cognisance in this matter, but intuition only has, and consequently that the wrong committed would not be against reason, but against intuition.

Our current speech accords with our literature in this view of the meaning of the word reason; whose efficiency, moreover, it endeavors to amplify, by surrounding it with satellites of adjectives formed from it, the principal of which are “reasonable” and “unreasonable.” Provided with this vocabulary, we pronounce it to be unreasonable to deny any truth whatever that can be well and clearly ascertained; and so far are we from reserving these adjectives for the occasion of demonstrative truth, and holding them inapplicable where self-evident or intuitive truth comes on the carpet, that we account it, if possible, still more unreasonable to deny the latter than the former.

But if the nomenclature adopted by Locke be the right one, there ought to be a change in these current modes of speaking and writing. One who should reject the proofs of Euclid, would be unreasonable; one who should maintain that Thurtel or Greenacre were innocent of murder, would be unreasonable; but, one who should deny the truth of any self-evident proposition, would not be unreasonable; for to say this, would be to say that reason has cognisance of such propositions, whereas, according to him, it is expressly not reason, but intuition that takes this office. The words “intuitional” and “unintuitional,” must be invented to supply the obvious need which the apparent gap discovers; there seems no other way of supplying it.

Lest I should be suspected of somewhat making up a case; of having, perhaps, represented not so much what Locke really means, as what he seems to mean, I will remind the reader that Locke is undertaking the formal definition of a word, and that on such a critical occasion, it is proper to give him credit for not meaning otherwise than he seems to mean.

The passage which is my text, will be found in the earlier part of the seventeenth chapter of the fourth book. Indeed, I could at once prove my indictment by citing a few words from it, accompanied by a comment of my own, had I any right to impose on the reader a belief in the discriminating fairness and matter-of-fact accuracy, both of my extracts and my comment.

I will, however, venture on such a step; I will suppose myself commenting on this passage, and proceed thus: Locke, it will be seen in this, his foremost and professed definition of the word reason, contrasts it with “sense and intuition.”

Whether he holds these to be identical with what he calls “the outward and the inward sense,” is not quite clear. That, however, is not the question.

He says, that these two faculties “reach but a very little way”; for that “the greatest part of our knowledge depends upon deductions and intermediate ideas.” Now, reason, he says, may be defined to be that faculty, whose specific office it is “to find out and apply” those intermediate ideas and deductions by which we obtain knowledge that consists of two kinds, one that which exalts us into “certainty,” the other that which, though less generous diet for the mind, we have constantly good ground for gladly acquiescing in, and which we call “probability.” So that, says Locke, if you ask, “What room is there for the exercise of any other faculty but outward sense and inward perception?” I can abundantly reply, “Very much.” I have shown you that without this “demonstrative” faculty, our knowledge would be but a skeleton; it would, indeed, not be properly speaking knowledge, but mere rudiments of knowledge.

Such is my interpretation of Locke’s definition of reason, in the proper and specific sense of this word. If it is strictly correct, as I believe the intelligent reader will find by reference, then it is Locke confounds reason with reasoning, mistakes a part for the whole, and the whole for a part, and acts similarly—to borrow his own way of illustration—to the representing a gallon to be a quart, or a half-sovereign to be a sovereign.