Mephistopheles

I would not lead you willingly astray, But as regards this science, you will find So hard it is to shun the erring way, And so much hidden poison lies therein, Which scarce can you discern from medicine. Here too it is the best, to listen but to one, And by the master's words to swear alone. To sum up all--To words hold fast! Then the safe gate securely pass'd, You'll reach the lane of certainty at last.