The Prog Mind

I
TRANSCENDENTAL ILLUSION 
WE have already entitled dialectic in general a logic of illu-
sion. This does not mean a doctrine of probability; for prob-
ability is truth, known however on insufficient grounds, and
the knowledge of which, though thus imperfect, is not on that
account deceptive; and such doctrine, accordingly, is not to be
separated from the analytic part of logic. Still less justification
have we for regarding appearance and illusion as being identi-
cal. For truth or illusion is not in the object, in so far as it is
intuited, but in the judgment about it, in so far as it is thought. 
It is therefore correct to say that the senses do not err -- not
because they always judge rightly but because they do not
judge at all. Truth and error, therefore, and consequently also
illusion as leading to error, are only to be found in the judg-
ment, i.e. only in the relation of the object to our understand-
ing. In any knowledge which completely accords with the laws
of understanding there is no error. In a representation of the
senses -- as containing no judgment whatsoever -- there is also
no error. No natural force can of itself deviate from its own
laws. Thus neither the understanding by itself (uninfluenced
by another cause), nor the senses by themselves, would fall
into error. The former would not, since, if it acts only accord-
ing to its own laws, the effect (the judgment) must necessarily
be in conformity with these laws; conformity with the laws
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of the understanding is the formal element in all truth. In
the senses there is no judgment whatsoever, neither a true
nor a false judgment. Now since we have no source of know-
ledge besides these two, it follows that error is brought about
solely by the unobserved influence of sensibility on the under-
standing, through which it happens that the subjective grounds
of the judgment enter into union with the objective grounds
and make these latter deviate from their true function, -- just
as a body in motion would always of itself continue in a
straight line in the same direction, but if influenced by another
force acting in another direction starts off into curvilinear
motion. In order to distinguish the specific action of under-
standing from the force which is intermixed with it, it is neces-
sary to regard the erroneous judgment as the diagonal between
two forces -- forces which determine the judgment in different
directions that enclose, as it were, an angle -- and to resolve
this composite action into the simple actions of the under-
standing and of the sensibility. In the case of pure a priori
judgments this is a task which falls to be discharged by tran-
scendental reflection, through which, as we have already shown,
every representation is assigned its place in the corresponding
faculty of knowledge, and by which the influence of the one
upon the other is therefore likewise distinguished. 
We are not here concerned with empirical (e.g. optical)
illusion, which occurs in the empirical employment of rules of
understanding that are otherwise correct, and through which
the faculty of judgment is misled by the influence of imagina-
tion; we are concerned only with transcendental illusion, which
exerts its influence on principles that are in no wise intended for
use in experience, in which case we should at least have had a
criterion of their correctness. In defiance of all the warnings of
criticism, it carries us altogether beyond the empirical employ-
ment of categories and puts us off with a merely deceptive exten-
sion of pure understanding. 
++ Sensibility, when subordinated to understanding, as the object
upon which the latter exercises its function, is the source of real
modes of knowledge. But the same sensibility, in so far as it in-
fluences the operation of understanding, and determines it to make
judgments, is the ground of error. 
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We shall entitle the principles whose
application is confined entirely within the limits of possible
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experience, immanent; and those, on the other hand, which
profess to pass beyond these limits, transcendent. In the case of
these latter, I am not referring to the transcendental employ-
ment or misemployment of the categories, which is merely an
error of the faculty of judgment when it is not duly curbed by
criticism, and therefore does not pay sufficient attention to the
bounds of the territory within which alone free play is allowed
to pure understanding. I mean actual principles which incite
us to tear down all those boundary-fences and to seize posses-
sion of an entirely new domain which recognises no limits of
demarcation. Thus transcendental and transcendent are not
interchangeable terms.