P. [92], § 45. Reason and Understanding. In the Wolfian School (e.g. in Baumgarten's Metaphysik, § 468) the term intellect (Verstand) is used of the general faculty of higher cognition, while ratio (Vernunft) specially denotes the power of seeing distinctly the connexions of things. So Wolff (Vernünftige Gedanken von Gott, &c. § 277) defines Verstand as 'the faculty of distinctly representing the possible,' and Vernunft (§ 368) as 'the faculty of seeing into the connexion of truths.' It is on this use of Reason as the faculty of inference that Kant's use of the term is founded: though it soon widely departs from its origin. For upon the 'formal' use of reason as the faculty of syllogising, Kant superinduces a transcendental use as a 'faculty of principles,' while the understanding is only 'a faculty of rules.' 'Reason,' in other words, 'itself begets conceptions,' and 'maxims, which it borrows neither from the senses nor from the understanding.' (Kritik d. r. Vern., Dialektik, Einleit. ii. A.) And the essential aim of Reason is to give unity to the various cognitions of understanding. While the unity given by understanding is 'unity of a possible experience,' that sought by reason is the discovery of an unconditioned which will complete the unity of the former (Dial. Einleit. iv), or of 'the totality of the conditions to a given conditioned.' (Dial, vii.)
It is this distinction of the terms which is dominant in Fichte and Hegel, where Verstand is the more practical intellect which seeks definite and restricted results and knowledges, while Vernunft is a deeper and higher power which aims at completeness. In Goethe's more reflective prose we see illustrations of this usage: e.g. Wilh. Meister's Wanderjahre, i. it is said to be the object of the 'reasonable' man 'das entgegengesetzte zu überschauen und in Uebereinstimmung zu bringen': or Bk. ii. Reasonable men when they have devised something verständig to get this or that difficulty out of the way, &c. Goethe, in his Sprüche in Prosa (896), Werke, iii. 281, says 'Reason has for its province the thing in process (das Werdende), understanding the thing completed (das Gewordene): the former does not trouble itself about the purpose, the latter asks not whence. Reason takes delight in developing; understanding wishes to keep everything as it is, so as to use it.' (Similarly in Eckermann's Convers. Feb. 13, 1829.) Cf. Oken, Naturphilosophie, § 2914. Verstand ist Microcosmus, Vernunft Macrocosmus.
Kant's use of the term Reason, coupled with his special view of Practical Reason and his use of the term Faith (Glaube), leads on to the terminology of Jacobi. In earlier writings Jacobi had insisted on the contrast between the superior authority of feeling and faith (which are in touch with truth) and the mechanical method of intelligence and reasoning (Verstand and Vernunft). At a later period however he changed and fixed the nomenclature of his distinction. What he had first called Glaube he latterly called Vernunft,—which is in brief a 'sense for the supersensible'—an intuition giving higher and complete or total knowledge—an immediate apprehension of the real and the true. As contrasted with this reasonable faith or feeling, he regards Verstand as a mere faculty of inference or derivative knowledge, referring one thing to another by the rule of identity.
This distinction which is substantially reproduced by Coleridge (though with certain clauses that show traces of Schellingian influence) has connexions—like so much else in Jacobi—with the usage of Schopenhauer, 'Nobody,' says Jacobi, 'has ever spoken of an animal Vernunft: a mere animal Verstand however we all know and speak of.' (Jacobi's Werke, iii. 8.) Schopenhauer repeats and enforces the remark. All animals possess, says Schopenhauer, the power of apprehending causality, of cognising objects: a power of immediate and intuitive knowledge of real things: this is Verstand. But Vernunft, which is peculiar to man, is the cognition of truth (not of reality): it is an abstract judgment with a sufficient reason (Welt als W. i. § 6).
One is tempted to connect the modern distinction with an older one which goes back in its origin to Plato and Aristotle, but takes form in the Neo-Platonist School, and enters the Latin world through Boëthius. Consol. Phil. iv. 6: Igitur uti est ad intellectum ratiocinatio, ad id quod est id quod gignitur, ad aeternitatem tempus, and in v. 4 there is a full distinction of sensus, imaginatio, ratio and intelligentia in ascending order. Ratio is the discursive knowledge of the idea (universali consideratione perpendit): intelligentia apprehends it at once, and as a simple forma (pura mentis acie contuetur): [cf. Stob. Ed. i. 826-832: Porphyr. Sentent.15]. Reasoning belongs to the human species, just as intelligence to the divine alone. Yet it is assumed—in an attempt to explain divine foreknowledge and defend freedom—that man may in some measure place himself on the divine standpoint (v. 5).
This contrast between a higher mental faculty (mens) and a lower (ratio) which even Aquinas adopts from the interpretation of Aristotle (Summa Theol. i. 79, 9) is the favourite weapon in the hands of mysticism. After the example of Dionysius Areop., Nicolaus of Cusa, Reuchlin, and other thinkers of the Renaissance depreciate mere discursive thought and logical reasoning. It is the inner mens—like a simple ray of light—penetrating by an immediate and indivisible act to the divine—which gives us access to the supreme science. This simplex intelligentia,— superior to imagination or reasoning—as Gerson says, Consid. de Th. 10, is sometimes named mens, sometimes Spiritus, the light of intelligence, the shadow of the angelical intellect, the divine light. From Scotus Erigena to Nicolas of Cusa one tradition is handed down: it is taken up by men like Everard Digby (in his Theoria Analytica) and the group of Cambridge Platonists and by Spinoza in the seventeenth century, and it reappears, profoundly modified, in the German idealism between 1790 and 1820.
P. [99], § 48. 'Science of Logic'; Hegel's large work on the subject, published between 1812-16. The discussions on the Antinomies belong chiefly to the first part of it.
P. [102], § 50. 'Natural Theology,' here to be taken in a narrower sense than in p. 73, where it is equivalent to Rational Theology in general. Here it means 'Physico-theology'—the argument from design in nature.
P. [103], § 50. Spinoza—defining God as 'the union of thought with extension.' This is not verbally accurate; for according to Ethica, i. pr. 11, God, or the substance, consists of infinite attributes, each of which expresses the eternal and infinite essence. But Spinoza mentions of 'attributes' only two: Ethica, ii. pr. 1. I Thought is an attribute of God: pr. 2, Extension is an attribute of God. And he adds, Ethica, i. pr. 10, Schol. 'All the attributes substance has were always in it together, nor can one be produced by another.' And in Ethica, ii. 7. Sch. it is said: 'Thinking substance and extended substance is one and the same substance which is comprehended now under this, now under that attribute.'
P. [110], § 54. 'Practical in the true sense of the word.' Cf. Kant, Werke, Ros. and Sch. i. 581: 'A great misunderstanding, exerting an injurious influence on scientific methods, prevails with regard to what should be considered "practical" in such sense as to justify its place in practical philosophy. Diplomacy and finance, rules of economy no less than rules of social intercourse, precepts of health and dietetic of the soul no less than the body, have been classed as practical philosophy on the mere ground that they all contain a collection of practical propositions. Hut although such practical propositions differ in mode of statement from the theoretical propositions which have for import the possibility of things and the exposition of their nature, they have the same content. "Practical," properly so called, are only those propositions which relate to Liberty under laws. All others whatever are nothing but the theory of what pertains to the nature of things—only that theory is brought to bear on the way in which the things may be produced by us in conformity with a principle; i.e. the possibility of the things is presented as the result of a voluntary action which itself too may be counted among physical causes.' And Kant, Werke, iv. 10. 'Hence a sum of practical precepts given by philosophy does not form a special part of it (co-ordinate with the theoretical) merely because they are practical. Practical they might be, even though their principle were wholly derived from the theoretical knowledge of nature,—as technico-practical rules. They are practical in the true sense, when and because their principle is not borrowed from the nature-conception (which is always sensuously conditioned) and rests therefore on the supersensible, which the conception of liberty alone makes knowable by formal laws. They are therefore ethico-practical, i.e. not merely precepts and rules with this or that intention, but laws without antecedent reference to ends and intentions.'