…in order to proceed from Von Uexküll’s theory to existential analysis, one must perform the Kantian-Copernican turn; instead of starting with nature and its planful system and dealing in natural science, one has to start at transcendental subjectivity and to proceed to existence as transcendence. Von Uexküll still throws both into one pot, as one deduces from the following ideas (which are quite impressive in themselves):
Let us take as an example a certain oak tree and then ask ourselves what kind of an environmental object will that oak tree be, in the environment of an owl that perches in its hollow trunk; in the environment of a singing bird that nests in its branches; of a fox which has its hole under its roots; of a woodpecker which goes after wood-fretters in its bark; in the environment of such a wood-fretter itself; of an ant which runs along its trunk, etc. And, eventually, we ask ourselves what the role of the oak tree is in the environment of a hunter, of a romantic young girl, and of a prosaic wood-merchant. The oak, being a closed planful system itself, is woven into ever new plans on numerous environment stages, the tracing of which is a genuine task for the science of nature.
Von Uexküll is a natural scientist and not a philosopher. So it should not be held against him that he, like most natural scientists, makes light of the essential difference between animal and man and does not “keep sacred” (Spemann) the division between them.
And yet, just at this point, this division becomes almost tangible. In the first place, the animal is tied to its “blueprint.” It cannot go beyond it, whereas human existence not only contains numerous possibilities of modes of being but is precisely rooted in this multifold potentiality of being.
Human existence affords the possibility of being a hunter, of being romantic, of being in business, and thus is free to design itself toward the most different potentialities of being; in other words, existence can “transcend” the being—in this case the being which is called “oak”—or make it accessible to itself, through the most diverse world-designs.
May, Rollo and Ernest Angel, Henri F. Ellenberger. Existence: A New Dimension in Psychiatry and Psychology. New York: Basic Book, Inc., 1958. 197–98. Print.