| For as regards nature, experience presents us with rules and is the source of truth, but in relation to ethical laws experience is the parent of illusion, and it is in the highest degree reprehensible to limit or to deduce the laws which dictate what I ought to do, from what is done. |
| We must, however, omit the consideration of these important subjects, the development of which is in reality the peculiar duty and dignity of philosophy, and confine ourselves for the present to the more humble but not less useful task of preparing a firm foundation for those majestic edifices of moral science. |
| For this foundation has been hitherto insecure from the many subterranean passages which reason in its confident but vain search for treasures has made in all directions. |
| Our present duty is to make ourselves perfectly acquainted with the transcendental use made of pure reason, its principles and ideas, that we may be able properly to determine and value its influence and real worth. |
| But before bringing these introductory remarks to a close, I beg those who really have philosophy at heart--and their number is but small--if they shall find themselves convinced by the considerations following as well as by those above, to exert themselves to preserve to the expression idea its original signification, and to take care that it be not lost among those other expressions by which all sorts of representations are loosely designated--that the interests of science may not thereby suffer. |
| We are in no want of words to denominate adequately every mode of representation, without the necessity of encroaching upon terms which are proper to others. |
| The following is a graduated list of them. |
| The genus is representation in general (representatio). |
| Under it stands representation with consciousness (perceptio). |
| A perception which relates solely to the subject as a modification of its state, is a sensation (sensatio), an objective perception is a cognition (cognitio). |
| A cognition is either an intuition or a conception (intuitus vel conceptus). |
| The former has an immediate relation to the object and is singular and individual; the latter has but a mediate relation, by means of a characteristic mark which may be common to several things. |
| A conception is either empirical or pure. |
| A pure conception, in so far as it has its origin in the understanding alone, and is not the conception of a pure sensuous image, is called notio. |
| A conception formed from notions, which transcends the possibility of experience, is an idea, or a conception of reason. |
| To one who has accustomed himself to these distinctions, it must be quite intolerable to hear the representation of the colour red called an idea. |
| It ought not even to be called a notion or conception of understanding. |
| SECTION II. Of Transcendental Ideas. |
| Transcendental analytic showed us how the mere logical form of our cognition can contain the origin of pure conceptions a priori, conceptions which represent objects antecedently to all experience, or rather, indicate the synthetical unity which alone renders possible an empirical cognition of objects. |
| The form of judgements--converted into a conception of the synthesis of intuitions--produced the categories which direct the employment of the understanding in experience. |
| This consideration warrants us to expect that the form of syllogisms, when applied to synthetical unity of intuitions, following the rule of the categories, will contain the origin of particular a priori conceptions, which we may call pure conceptions of reason or transcendental ideas, and which will determine the use of the understanding in the totality of experience according to principles. |