Nietzsche Undoes Himself
Aside from whatever mistakes he may have made, the most important thing to understand about Nietzsche is that he undoes himself. I've already written that he undoes himself, in a more specific context, but this can be understood more generally. At every level, he undoes himself.
Perhaps Nietzsche's greatest contribution to philosophy is his writing about ressentiment, and everything that he derives from that fundamental element. (I do not think he was the first to discover ressentiment; I find it, among other places, in the writings of Rousseau, not to mention Goethe. But no one saw the significance of ressentiment as deeply as Nietzsche.) But once one realizes how deeply resentful Nietzsche himself was, and how his ressentiment motivated all of his own ideas, everything is transformed, inverted, undone. Take, for instance, Nietzsche's constant, bitter sniping against Socrates, "that little worm": a spirit driven less by ressentiment would be grateful to Socrates. And deep down, I think Nietzsche did have both admiration and gratitude towards all of the old masters, even though, at a superficial level, he made himself appear to be the spirit of criticism personified.
I do not believe this to have been a mistake on Nietzsche's part. I believe that he set up his writing this way on purpose, like a line of dominoes, for the reader to knock down.
Why does Nietzsche wear all of his spleen on his sleeve? Of course, partly this is because sanctimonious pleasantries are boring, and spiteful wit is delightfully entertaining. But there's more to it than that.
All of Nietzsche's philosophy is a "joke," but the cruelest, most devastating joke - at Nietzsche's own expense. Ridendo dicere severum. This is the most lacerating, penetrating, insightful form of self-consciousness that the world has ever known. Nietzsche spares nothing, leaves nothing out, softens nothing, protects nothing - he utterly opens himself to you.
Perhaps all the greatest philosophers undo themselves. Marx, for instance, obviously undoes himself: he is one of those bourgeois intellectuals that he criticizes, and all of his work can be read as self-criticism. But Nietzsche undoes himself in a more radical way, causing himself to disappear.
We write about metabolism. Nietzsche writes that German intellect "took its origin... in sadly disordered intestines.... German intellect is indigestion." He sees the Idealism that abounded in his day as something fundamentally half-digested, and saw all the young men in Germany walking around with half-digested Hegel sticking in their gullets like a sausage. The goal, then, should be either a more selective diet, in which we avoid certain foods altogether, or, the capacity to digest fully. Once one has digested Nietzsche fully, he ceases to exist within oneself. He becomes fully transparent - he dissolves.