Textual Extract
from

"The Critique
of Pure Reason"

by
Immanuel Kant.

WHETHER the elaboration of cognitions which belong to the business of Reason, takes the sure march of a science or not, is easily judged of by the result. If, after many arrangements and preparations made, so soon as the object is approached, the elaboration comes to a stand, or, if in order to reach this object we must go back again frequently, and strike into another path, and besides, if it be not possible to render different fellow labourers unanimous as to the mode in which the common end is to be pursued; we may then always be convinced, that such a study is still far from taking the sure course of a science, but is a mere feeler, and it is already a merit, as regards reason, to discover this path, in case it is possible, although much must be given up as vain, which was comprised without due consideration, in the object previously proposed.
  That Logic has proceeded in this sure course, already from the earliest times, may be seen from this, that since Aristotle it has not been necessitated to retrace a step, unless, perhaps, we may be disposed to reckon the brushing away of some superfluous subtleties from it, or the clearer determination of what has been propounded, but which belong more to the elegance than the certainty of the science, as ameliorations. It is however remarkable with respect to Logic, that hitherto it has not been able to make any step forwards, and therefore to all appearance seems to be concluded and completed. For, if some moderns thought to extend it, by this, that they pushed in, partly psychological chapters of the different cognition-faculties (Imagination and Wit), partly metaphysical, as to the origin of cognition, or as to the different kind of certitude, according to the difference of objects (Idealism, Scepticism, etc.), partly anthropological, of prejudices (the causes of the same and remedies); this then proceeded from their ignorance of the particular nature of this science. It is not augmentation, but disfiguration of the sciences, when we allow their boundaries to run into one another; but the boundary of Logic is very closely determined by this, that it is a science which fully exposes and strictly shows nothing but the formal rules of all Thinking, (whether this be à priori or empirical - have whatever origin or object it will - meet in our mind with accidental or natural impediments).