What I write here is not my teaching, but my study; it is not a lesson for others, but for me. And yet it should not be held against me if I publish what I write. What is useful to me may also by accident be useful to another. Moreover, I am not spoiling anything, I am only using what is mine. And if I play the fool, it is at my expense and without harm to anyone. For it is a folly that will die with me, and will have no consequences.