open meant by Rilke is not the open in the sense of the unconcealed. Rilke knows and suspects nothing of alētheia, no more than Nietzsche does.”2 At work in both Nietzsche and Rilke is that oblivion of being “which lies at the foundation of the biologism of the nineteenth century and of psychoanalysis” and whose ultimate consequence is “a monstrous anthropomorphization of . . . the animal and a corresponding animalization of man.”3 Only man, indeed only the essential gaze of authentic thought, can see the open which names the unconcealedness of beings. The animal, on the contrary, never sees this open.
Therefore neither can an animal move about in the closed as such, no more than it can comport itself toward the concealed. The animal is excluded from the essential domain of the conflict between unconcealedness and concealedness. The sign of such an exclusion is that no animal or plant “has the word.”4
At this point Heidegger, in an extremely dense page, explicitly evokes the problem of the difference between animal environment and human world which was at the center of the 1929–30 course:
For the animal is in relation to his circle of food, prey, and other animals of its own kind, and it is so in a way essentially different from the way the stone is related to the earth upon which it lies. In the circle of the living things characterized as plant or animal we find the peculiar stirring of a motility by which the living being is “stimulated,” i.e., excited to an emerging into a circle of excitability on the basis of which it includes other things in the circle of its stirring. But no motility or excitability of plants and animals can ever bring the living thing into the free in such a way that what is stimulated could ever let the thing which excites “be” what it is even merely as exciting, not to mention what it is before the excitation and without it. Plant and animal depend on something outside of themselves without ever “seeing” either the outside or the inside, i.e., without ever seeing their being unconcealed in the free of being. It would never be possible for a stone, any more than for an airplane, to elevate itself toward the sun in jubilation and to stir like the lark, and yet not even the lark sees the open.5
4. Ibid., 159–60; original, 237.
5. Ibid., 160; original, 237–38.