GA 33

Aristoteles, Metaphysik Θ 1–3, Von Wesen und Wirklichkeit der Kraft

Aristotle's Metaphysics Theta 1-3: On the Essence and Actuality of Force

This Summer Semester 1931 course, originally given under the title Interpretations from Ancient Philosophy, is a reinterpretation of Aristotelian ontology that was inspired by Heidegger’s reading of Friedrich Nietzsche’s account of pre-Socratic philosophy. From Nietzsche, he borrowed the insight into the fundamental difference between pre-Socratic thought and the philosophy of Plato and Aristotle. This insight led in turn to his conception of the history of being. The course consists of two parts: an introduction and an interpretation of Aristotle’s Metaphysics.

In the introduction, Heidegger searches for an encompassing horizon from which Aristotle’s thought may be explained. He sketches the basic structure of Aristotelian ontology, and focuses his attention on the conflict between the Oneness of being and the manifold senses or meanings of being. Aristotle states, on the one hand, that being is said in a fourfold way: (1) To be accidental; (2) to be true or false; (3) according to the figures of categories; and (4) to be potentially (δύναμις) or actually (ἐνέργεια). On the other hand, he is still under the spell of the saying of Parmenides that being is One. The meanings of being, which determine the being of entities, cannot be reduced to each other, and stand in opposition to the Oneness of being. Aristotle tries to explain the relationship between being as one and as manifold by analogy. However, he fails to explain the essence of analogy and to show that the relationship between being one and manifold can be understood as analogy. He also does not explain why being unfolds itself in a fourfold way. In the unconcealment of being as the fourfold being of entities, being as the One remains concealed. The ontological difference between being and entities makes truth (ἀλήθεια) possible, and is the forgotten ground of Greek thought and the history of philosophy as metaphysics.

The main part of the course is a comprehensive interpretation of Aristotle’s conception of the essence and actuality of force. Force is the ἀρχή, that is, the setting point for a transformation or movement of an entity into something else. Force shows itself as the toleration of or resistance against transformation. Heidegger distinguishes between an ontological and an ontic concept of force in Aristotle’s philosophy. Ontologically, force is the capacity of acting (ποιείν) and undergoing (πάσχειν) as one. It is both the starting point of a capacity to transform and a capacity to be transformed. Ontically, force is the actualization of an entity as either the starting point of an action upon another entity, or the undergoing of the action of another entity. The opposite of force is incapacity or impotency.

Aristotle understands the actuality of force as a form of having. Having the force or capacity to do something means being able to do something. The Megaric school, on the other hand, holds that the actuality of force is identical to its actualization. According to Heidegger, the real issue between Aristotle and the Megaric school remains implicit. This issue is the basic question of philosophy: What is being? For Aristotle and the Megaric school, as for all Greeks, being means presence. Aristotle claims that the Megaric concept of presence is too narrow. He denies that actuality, ἐνέργεια, is the only and fundamental way a force is present and real. He distinguishes three ways in which force can be present: (1) A force can be present as capacity, e.g., a shoemaker has the capacity to make shoes; (2) a force can be present as the actualization of a capacity, e.g., the making of shoes; (3) a force can be present in its product, e.g., the shoe as finished product of shoemaking.

In the next step of his argumentation, Aristotle shows that perception, αἴσθησις, actualizes itself as the disclosing of entities in their being. The actuality of something present-at-hand is only possible if the perceptible is not grounded in the actualization of perception. The unasked question of Aristotle’s and all later philosophy is how the unconcealment of being is possible. Αἴσθησις is a form of uncovering, ἀληθεύειν, that is, to take something as true or to take something from concealment in perception. Aristotle defines force in its actuality as that for which nothing is unworkable, when it actualizes the capacity that it is said to have. He thus addresses the problem of the essence of an entity in its fullest sense. The essence of an entity is disclosed when the kind of actuality or existence that belongs to this essence is revealed. After Aristotle, philosophy fell prey to the ambiguity of this forgottennness, which is at the same time the condition of possibility of the history of philosophy as metaphysics.