Groundwork for the Metaphysics of Morals, published in 1785, with the following sentences:

Ancient Greek philosophy was divided into three branches of knowledge: physics, ethics, and logic. This classification fits the nature of this manner of inquiry perfectly, and one cannot improve upon it, except perhaps to add the principle upon which it is based, in order to, on the one hand, thereby assure oneself of its comprehensiveness, and, on the other hand, in order to be able to determine the necessary subdivisions correctly.1

Now, surely that which, according to Kant, still needs to be added to this classification—namely, the ‘principle’ of classification (i.e., that from which it proceeds and in its necessity is shaped and sustained)—is the most difficult. Whether and in what way Kant himself found this principle, and whether and in what way this principle was exhibited in the metaphysical systems of German Idealism, cannot be expounded upon here: for something else is more pressing. [230]


b) Logic and the inhibiting of the unfolding of the essence of the Λόγος

In order to attain the correct insight into the essence and meaning of logic, we must consider that the ‘revolution’ of thinking brought into philosophy by Kant was carried out in the realm of logic. Before even diving into the matter, we can already see this in the titles of his three main works: Critique of Pure Reason, Critique of Practical Reason, and Critique of Judgment. At issue in each case is reason, i.e., ratio, i.e., the faculty of judgment, i.e., thinking, i.e., a doctrine of reason, i.e., ‘logic.’ The decisive step in thinking undertaken by Kant—a thinking about whose essence and scope he also possessed a clear knowledge—is the step away from a prior logic toward a new ‘logic’ that he named “transcendental logic.” ‘Logic,’ in various extended forms and permutations, thus becomes the core of thinking immediately following Kant, specifically in the metaphysics of Fichte, Schelling, and Hegel. Indeed, the entirety of thinking between 1790 and 1830 is deeply determined by Kant’s new ‘logic.’ The meaning of Kant’s thinking for Heinrich von Kleist, both in a positive and a negative sense, is well-known. Even Goethe’s thinking, in those occasional moments when it brushes up against philosophy (in odd ways), only attains its proper lucidity and sharpness from



1 Kant, Werke, IV, 153.


174    Logic: Heraclitus’s Doctrine of the Logos


Heraclitus (GA 55) by Martin Heidegger