And further, if this proposition be not true, there is no right reasoning in Euclid; nor can we be sure that what is there demonstrated is true. But to say this, I am sure, is absurd. Nor do I desire that this proposition, which I here maintain, should be esteemed more certain than those demonstrated by him: and so certain it must be, because there can be no certainty in them, if this be not true.
The great objection against all this is taken from the many instances of false reasoning and ignorance, with which the practices, discourses, writings of mankind are too justly taxed. But, in answer to it, I would have it minded that I do not say men may not, by virtue of their freedom, break off their meditations and inquiries prematurely, before they have taken a sufficient survey of things; that they may not be prepossessed with inveterate errors, biased by interest, or carried violently down with the stream of a sect or fashion, or dazzled by some darling notion or bright name;132 that they may not be unprovided of a competent flock of præcognita and preparative knowledge; that (among other things) they may not be ignorant of the very nature of reasoning, and what it is that gives sinews to an inference, and makes it just; that they may not want philosophy, history, or other learning, requisite to the understanding and stating of the question truly; that they may not have the confidence to pretend to abilities which they have not, and boldly to judge of things as if they were qualified, when they are not; that they may not be impotent in their elocution, and misrepresent their own thoughts, by expressing themselves ill, even when within themselves they reason well; that many understandings may not be naturally gross, good heads often indisposed, and the ablest judges sometimes overseen, through inadvertence or haste—I say none of these things. The contrary, I confess, is manifest: and it is in opposition to those errors, which appear in these cases under the name of reason, that we are forced to add the epithet right, and to say right reason instead of reason only, to distinguish it from that which wrongfully assumes that appellation. Nor, moreover, do I say that by reasoning the truth is to be discovered in every case: that would imply an extent of knowledge which we cannot pretend to. I only say that there is such a thing as right reason, and truth discoverable by it.
I might add that he whose faculties are entire and sound, and who by a proper exercise of his mind in scientific studies first opens and enlarges its capacity, and renders his intellectuals active and penetrating; takes care to furnish himself with such leading truths as may be useful to him, and of which he is assured in his own breast; and in treating any subject keeps them still in his eye, so that his discourse may be agreeable to them: I say, such a one is not in much danger of concluding falsely. He must either determine rightly, or soon find that the subject lies out of his reach. However he will be sensible that there are many things, within his sphere, concerning which he may reason; and that there are truths to be found, by this use of his faculties, in which he may securely acquiesce.
Thus, that question supposed to be asked, “How shall a man know what is true?” is in part answered. More shall be added by and by: only a proposition or two, which ought not to be omitted, must be first inserted.
X. To act according to right reason, and to act according to truth, are in effect the same thing. For in which sense soever the word “reason” is taken, it will stand either for truth itself, or for that which is instrumental in discovering and proving it to be such: and then, with respect to this latter sense, whoever is guided by that faculty, whose office consists in distinguishing and pointing out truth, must be a follower of truth, and act agreeably to it. For to be governed by any faculty or power is to act according to the genuine decisions and dictates of it.
That reason which is right (by the meaning of the words) must conclude rightly: but this it cannot do if the conclusion is not true, or truth.
That is (for so I would be understood), if the principles and premises from whence it results are true,133 and certainly known to be so, the conclusion may be taken as certain and absolute truth; but otherwise the truth obtained at the end of the argument is but hypothetical, or only this: that such a thing is so, if such another, or such others are so or so.
XI. To be governed by reason is the general law imposed by the Author of nature134 upon them whose uppermost faculty is reason; as the dictates of it, in particular cases, are the particular laws to which they are subject. As there are beings which have not so much as sense, and others that have no faculty above it; so there may be some who are endowed with reason, but have nothing higher than that. It is sufficient, at present, to suppose there may be such. And then if reason be the uppermost faculty, it has a right to control the rest by being such. As, in sensitive animals, sense commands gravitation and mechanical motions in those instances for which their senses are given, and carries them out into spontaneous acts: so, in
