GA 10

Der Satz vom Grund

The Principle of Reason

This Winter Semester 1955–56 lecture course is the last one Heidegger gave at the University of Freiburg. It is a retrieval of the fundamental question of metaphysics and brings this question to light in the questionability of its ground. The principle of reason, nothing is without reason, assert that our understanding looks always and everywhere for the reason why something is. Human representation searches everywhere for a founding. The phenomenon that is brought to light in the principle of reason is older than the explicit formulation of this principle as principle by Gottfried Wilhelm Leibniz. He stated that each entity has its reason. Although it is impossible to verify the principle of reason empirically, it asserts something that is necessary. It is the fundamental principle of all other fundamental principles, like the principle of identity and the principle of contradiction.

The principle of reason presupposes that we know what a reason is. After an interpretation of the different ways in which reason has been thought, Heidegger plays the principle of reason off against the poetic experience of Angelus Silesius that the “rose is without why.” Human beings and the rose are not without reason, but like the rose, human beings can be without always looking for the cause of entities. The principle of reason says that to the being of entities belongs something like a reason or cause. Yet, we must differentiate between being and reason. Reason does not reach being, as such. Being is the abground (Abgrund) and, as such, without reason. When we recollect this truth, we can read the principle of reason in a different way. Instead of nothing is without reason, we can also read, nothing is without reason. The emphasis lies now on the relation between being and reason.

During the incubation period of the principle of reason, the destiny of being changed several times, although being, as such, remained concealed. Being withdraws from the unconcealment of entities and can therefore never be explained by an entity. Being has no reason. Human beings stand in the open of the projection of being, and thereby have the possibility to respond to the being of entities. In this way, thinking opens itself for the destiny of being, and may move beyond metaphysics. Metaphysics thinks being as reason or ground, and forgets that if being itself is grounding, being itself can have no ground. Thinking can only reach being if it is prepared to leap into the ungrounded abground of its being without why. Or to use a word of Heraclitus, being is the mystery of play. The other kind of commemorative thinking may free human beings from the frenzy and madness of calculative thinking and technology.

GA 10