On Opinion, Belief, and Knowledge

To begin our consideration of the modes of which man consists, we shall state (1) what they are, (2) their effects, and (3) their cause.

As regards the first, let us begin with those that are first known to us: namely, certain ideas or the consciousness of the knowledge of ourselves, and of the things which are outside us.

Now we get these ideas (1) either merely through belief (which belief arises either from experience, or from hearsay), (2) or, in the second place, we acquire them by way of a true belief, (3) or, thirdly, we have them as the result of clear and distinct conception.

The first is commonly subject to error.

The second and third, however, although they differ from one another, cannot err.

To make all this somewhat clearer and more intelligible, we shall give the following illustration taken from the Rule of Three.

Someone has just heard it said that if, in the Rule of Three, the second number is multiplied by the third, and then divided by the first, a fourth number will then be obtained which has the same relation to the third as the second has to the first. And not-withstanding the possibility that he who put this before him might have been lying, he still made his calculations accordingly, and he did so without having acquired any more knowledge of the Rule of Three than a blind man has of color, so that whatever he may have said about it, he simply repeated as a parrot repeats what it has been taught.

Another, having a more active intelligence, is not so easily satisfied with mere hearsay, but tests it by some actual calculations, and when he finds that they agree with it, then he gives credence to it. But we have rightly said that this one also is subject to error; for how can he possibly be sure that his experience of a few particulars can serve him as a rule for all?

A third, who is not satisfied with hearsay, because it may deceive, nor with experience of a few particulars, because this cannot possibly serve as a rule, examines it in the light of true Reason, which, when properly applied, has never deceived. This then tells him that on account of the nature of the proportion in these numbers it had to be so, and could not happen otherwise.

A fourth, however, having the clearest knowledge of all, has no need of hearsay, or experience, or the art of reasoning, because by his penetration he sees the proportion in all such cogitations intuitively.

We come now to the consideration of the effects of the different grades of knowledge, of which we spoke in the preceding chapter, and, in passing as it were, we shall explain what Opinion, Belief, and clear Knowledge are.

The first [kind of knowledge], then, we call Opinion, the second Belief, but the third is what we call clear Knowledge.

We call it Opinion because it is subject to error, and has no place when we are sure of anything, but only in those cases when we are said to guess and to surmise. The second we call Belief, because the things we apprehend only with our reason are not seen by us, but are only known to us through the conviction of our understanding that it must be so and not otherwise. But we call that clear Knowledge which comes, not from our being convinced by reasons, but from our feeling and enjoying the thing itself, and it surpasses the others by far.

After these preliminary remarks let us now turn to their effects. Of these we say this, namely, that from the first proceed all the “passions” which are opposed to good reason; from the second, the good desires; and from the third, true and sincere Love, with all its offshoots.

We thus maintain that Knowledge is the proximate cause of all the “passions” in the soul. For we consider it once for all impossible that anyone, who neither thinks nor knows in any of the preceding ways and manners, should be capable of being incited to Love or Desire or any other mode of emotion.