Kant, Immanuel. Groundwork of the Metaphysics of Morals. Trans. by H. J. Paton. Harper & Row: New York, 1964.
Kant, Immanuel. Critique of Pure Reason.
Kant, Immanuel. Critique of Practical Reason.
Kant, Immanuel. Religion Within the Limits of Reason Alone.
Hegel, Georg Wilhelm Friedrich. Philosophy of Right.
Hegel, Georg Wilhelm Friedrich. Reason in History.
Nietzsche, Freidrich. Beyond Good and Evil.
The last note on Darwin and evolution displays a common misconception about evolution, that is, the anthropomorphism of a process. Organs do not develop to help with survival, the organs that are best suited for survival survive. There is no purpose in an organ's origins.