 Schopenhauer devotes many pages to empirical descriptions of the similarities between the forces at work throughout the rest of nature and the merely apparently rational but really non-rational character of our own behavior, but of course the character of things in themselves cannot be inferred directly from any amount of empirical data; Schopenhauer derives his conclusion not from all this empirical illustration but rather from our allegedly immediate rather than empirical insight into the character of our own wills and the very problematic premise that at bottom everything is essentially one. His position thus begins from an epistemological premise, namely that we can know ultimate reality through knowing ourselves, and reaches an ontological conclusion, that ultimate reality must be like ourselves, but in opposition to Kant and the other German idealists he assumes that our own nature is essentially non-rational and therefore that the ultimate character of reality, although it is in a certain sense like the mental, is also fundamentally non-rational.