I am really amazed, really delighted! I have a precursor, and what a precursor! I hardly knew Spinoza: what brought me to him now was the guidance of instinct. Not only is his whole tendency like my own—to make knowledge the most powerful passion—but also in five main points of his doctrine I find myself; this most abnormal and lonely thinker is closest to me in these five points precisely: he denies free will, purposes, the moral world order, the nonegoisitical, evil; of course the differences are enormous, but they are differences more of period, culture, field of knowledge. In summa: my solitariness which, as on very high mountains, has often, often made me gasp for breath and lose blood, is now at least a solitude for two. Strange!
Friedrich Nietzsche, letter to Franz Overbeck, 1881. Translated by Christopher Middleton