Philosophy aspires to the impersonal truth but, like a rocket that fails to achieve escape velocity, it remains forever in orbit around the personal, tied to it, expressive of it. This ineluctable tie-in to the personal works against philosophy's pursuit of the universal. And so, while in aspiration one, in execution philosophy is many, which is to say that there is no philosophy, only philosophies. There is no philosophy except in aspiration and in the drive to the truth that breaks free from the personal. In execution, philosophy does not break free; it breaks apart into philosophies.
And so I cannot disagree with Friedrich Nietzsche (1844-1900) who, in Part One of Beyond Good and Evil, "On the Prejudices of the Philosophers," tells us that "every great philosophy" has bisher, hitherto, been eine Selbsterkenntnis ihres Urhebers, a confession or self-cognition of its author, and eine Art ungewollter und unvermerkter mémoires, a kind of involuntary and unconscious memoir.
That's right. But what did old Fritz mean by 'hitherto'? That he was an exception? But he was surely no exception. His philosophy was just another confession of its author, just another rocket aimed at truth that failed to achieve escape velocity and fell back into orbit around the personal-all-too-personal.
What a rich specimen of humanity he was. He did a lot of damage, but he dug deep and he dug fearlessly and at personal cost. We honor him for that.