| I. Of Transcendental Illusory Appearance. |
| We termed dialectic in general a logic of appearance. |
| This does not signify a doctrine of probability; for probability is truth, only cognized upon insufficient grounds, and though the information it gives us is imperfect, it is not therefore deceitful. |
| Hence it must not be separated from the analytical part of logic. |
| Still less must phenomenon and appearance be held to be identical. |
| For truth or illusory appearance does not reside in the object, in so far as it is intuited, but in the judgement upon the object, in so far as it is thought. |
| It is, therefore, quite correct to say that the senses do not err, not because they always judge correctly, but because they do not judge at all. |
| Hence truth and error, consequently also, illusory appearance as the cause of error, are only to be found in a judgement, that is, in the relation of an object to our understanding. |
| In a cognition which completely harmonizes with the laws of the understanding, no error can exist. |
| In a representation of the senses--as not containing any judgement--there is also no error. |
| But no power of nature can of itself deviate from its own laws. |
| Hence neither the understanding per se (without the influence of another cause), nor the senses per se, would fall into error; the former could not, because, if it acts only according to its own laws, the effect (the judgement) must necessarily accord with these laws. |
| But in accordance with the laws of the understanding consists the formal element in all truth. |
| In the senses there is no judgement--neither a true nor a false one. |
| But, as we have no source of cognition besides these two, it follows that error is caused solely by the unobserved influence of the sensibility upon the understanding. |
| And thus it happens that the subjective grounds of a judgement and are confounded with the objective, and cause them to deviate from their proper determination,* just as a body in motion would always of itself proceed in a straight line, but if another impetus gives to it a different direction, it will then start off into a curvilinear line of motion. |
| To distinguish the peculiar action of the understanding from the power which mingles with it, it is necessary to consider an erroneous judgement as the diagonal between two forces, that determine the judgement in two different directions, which, as it were, form an angle, and to resolve this composite operation into the simple ones of the understanding and the sensibility. |
| In pure a priori judgements this must be done by means of transcendental reflection, whereby, as has been already shown, each representation has its place appointed in the corresponding faculty of cognition, and consequently the influence of the one faculty upon the other is made apparent. |
| [*Footnote; Sensibility, subjected to the understanding, as the object upon which the understanding employs its functions, is the source of real cognitions. |
| But, in so far as it exercises an influence upon the action of the understanding and determines it to judgement, sensibility is itself the cause of error.] |
| It is not at present our business to treat of empirical illusory appearance (for example, optical illusion), which occurs in the empirical application of otherwise correct rules of the understanding, and in which the judgement is misled by the influence of imagination. |