| I can only maintain, that is, affirm as necessarily valid for every one, that which produces conviction. |
| Persuasion I may keep for myself, if it is agreeable to me; but I cannot, and ought not, to attempt to impose it as binding upon others. |
| Holding for true, or the subjective validity of a judgement in relation to conviction (which is, at the same time, objectively valid), has the three following degrees; opinion, belief, and knowledge. |
| Opinion is a consciously insufficient judgement, subjectively as well as objectively. |
| Belief is subjectively sufficient, but is recognized as being objectively insufficient. |
| Knowledge is both subjectively and objectively sufficient. |
| Subjective sufficiency is termed conviction (for myself); objective sufficiency is termed certainty (for all). |
| I need not dwell longer on the explanation of such simple conceptions. |
| I must never venture to be of opinion, without knowing something, at least, by which my judgement, in itself merely problematical, is brought into connection with the truth--which connection, although not perfect, is still something more than an arbitrary fiction. |
| Moreover, the law of such a connection must be certain. |
| For if, in relation to this law, I have nothing more than opinion, my judgement is but a play of the imagination, without the least relation to truth. |
| In the judgements of pure reason, opinion has no place. |
| For, as they do not rest on empirical grounds and as the sphere of pure reason is that of necessary truth and a priori cognition, the principle of connection in it requires universality and necessity, and consequently perfect certainty--otherwise we should have no guide to the truth at all. |
| Hence it is absurd to have an opinion in pure mathematics; we must know, or abstain from forming a judgement altogether. |
| The case is the same with the maxims of morality. |
| For we must not hazard an action on the mere opinion that it is allowed, but we must know it to be so. |
| In the transcendental sphere of reason, on the other hand, the term opinion is too weak, while the word knowledge is too strong. |
| From the merely speculative point of view, therefore, we cannot form a judgement at all. |
| For the subjective grounds of a judgement, such as produce belief, cannot be admitted in speculative inquiries, inasmuch as they cannot stand without empirical support and are incapable of being communicated to others in equal measure. |
| But it is only from the practical point of view that a theoretically insufficient judgement can be termed belief. |
| Now the practical reference is either to skill or to morality; to the former, when the end proposed is arbitrary and accidental, to the latter, when it is absolutely necessary. |