"Here stand I, ach, Philosophy Behind me, Law and Medicine too And to my cost theology- All these I have sweated through and through And now you see me a poor fool As wise as when I entered school! They call me master, they call me doctor, Ten years now I have dragged my college Along by the nose through Zig and Zag Through up and down and round and round And this is all that I have found- The impossibility of knowledge! It is this that burns away my heart; Of course I am cleverer than the Quacks Than master and doctor, than Clerk or Priest, I suffer no scruple or doubt in the least, I have no qualms about devil or burning Which is just why all joy is torn away from me, I cannot presume to make use of my learning, I cannot presume I could open my mind To proselytize and improve mankind."This quote is of which Author?