Plato’s Forms and Kant’s a priori

In ‘An afternoon at Balliol’ (posted on May 17) I wrote: ‘The philosophic affinity between Plato’s Forms and Kant’s a priori concepts is obvious.’ As soon as I posted the text, I began to have doubts whether I was entitled to make that statement, for in making it I basically relied on Tennemann: ‘In the last brief section of his Critique of Pure Reason Kant proposes the history of pure reason (Die Geschichte der reinen Vernunft) as the task that remains to be done; it is to be the history of philosophy as it culminated in the discovery of truth. A German philosopher W. G. Tennemann undertook this task, and he began to fulfil it with his System of Platonic Philosophy (System der Platonischen Philosophie, published in 1792). On the assumption that the more truth a philosophic system contains, the more it approximates Kant, he rejected the ancient dating of Plato’s Phaedrus as his first dialogue. In his view, Plato’s philosophy developed towards the theory of Forms in the Phaedrus, as all subsequent philosophy developed towards Kant’s idea of a priori.’ – I had to return to Kant and see, whether Tennemann’s claim, which I had appropriated, could be justified.

At first glance, the claim is untenable. In the ‘Introduction’ to the 2^nd edition of the Critique Kant says: ‘That all our knowledge begins with experience there can be no doubt … In respect of time, therefore, no knowledge of ours is antecedent to experience, but begins with it’ (tr. J. M. D. Meiklejohn).

Plato says in the Phaedrus that only the soul that has beheld the Forms can be incarnated in the human bodily shape: ‘Human beings must understand what is said according to Form (dei gar anthrȏpon sunienai kat’ eidos legomenon), for what is spoken passes from a plurality of perceptions (ek pollȏn ion aisthêseȏn) and must be gathered together into unity by reason (eis hen logismȏi sunairoumenon); and this is a recollection of those entities (touto d’ estin anamnêsis ekeinȏn) which our soul once beheld (ha pot’ eiden hêmȏn hê psuchê) as it journeyed with god (sumporeutheisa theȏi) … when it rose up to what truly is (ankupsasa eis to on ontȏs)’. (249b5-c4).

Referring presumably to the opening paragraph in Kant’s ‘Introduction’, quoted above, Raymund Schmidt, the editor of the 1956 edition, writes in his ‘Sachregister’ that a priori in Kant does not mean a priority in time, being inborn, but a transcendental priority (a priori: bei Kant nicht in zeitlicher Bedeutung = angeboren, sondern in transcendentaler). But note the second paragraph of Kant’s ‘Introduction’: ‘But, though all our knowledge begins with experience (Wenn aber gleich alle unsere Erkenntnis mit der Erfahrung anhebt,), it by no means follows that all arises out of experience (so entspringt sie darum doch nicht eben alle aus der Erfahrung.). For, on the contrary, it is quite possible (Denn es könnte wohl sein,) that our empirical knowledge (dass selbst unsere Erfahrungserkenntnis) is a compound of that (ein Zusammengesetztes aus dem sei,) which we receive through impressions (was wir durch Eindrücke empfangen,), and that (und dem,) which the faculty of cognition supplies from itself (was unser eigenes Erkenntnisvermögen aus sich selbst hergibt,) (sensuous impressions giving merely the occasion (durch sinnliche Eindrücke bloss veranlasst)), an addition which we cannot distinguish from the original element given by sense (welchen Zusatz wir von jenem Grundstoffe nicht eher unterscheiden,), till long practice has made us attentive to, and skilful in separating it (als bis lange Űbung uns darauf aufmerksam und zur Absonderung desselben geschickt gemacht hat.)’ (tr. J. M. D. Meiklejohn).

The following passage from the 1^st part of the ‘Transcendental Aesthetic’ fully justifies Tennemann’s view that Plato’s Forms in the Phaedrus point to Kant’s a priori: ‘That which in the phenomenon corresponds to the sensation, I term its matter (In der Erscheinung nenne ich das, was der Empfindung korrespondirt, die Materie derselben,); but that (dasjenige aber,) which effects (welches macht,) that the content of the phenomenon (dass das Mannigfaltige der Erscheinung) can be arranged under certain relations (in gewissen Verhältnissen geordnet werden kann,), I call its form (nenne ich die Form der Erscheinung.). But that in which our sensations are merely arranged (Da das, worinnen sich die Empfindungen allein ordnen), and by which they are susceptible of assuming a certain form (und in gewisse Form gestellt werden können,), cannot be itself sensation (nicht wiederum Empfindung sein kann,). It is, then, the matter of all phenomena that is given to us a posteriori (so ist uns zwar die Materie aller Erscheinung nur a posteriori gegeben,); the form must lie ready a priori for them in the mind (die Form derselben aber muss zu ihnen insgesamt im Gemüte a priori bereitliegen,), and consequently can be regarded separately from all sensation (und daher abgesondert von aller Empfindung können betrachtet warden,)’ (tr. J. M. D. Meiklejohn). (Immanuel Kant, Kritik der reinen Vernunft, nach der ersten und zweiten Original-Ausgabe neu herausgegeben von Raymund Schmidt, Felix Meiner Verlag, Hamburg 1956, p. 64) –I apologize for not revising Meiklejohn’s translation; I let it stand, for it does not distort Kant’s thought significantly.