What we find in them, and what is hardly to be found elsewhere, is a mirror of one of the world's greatest spirits in the process of attaining self-knowledge and self-mastery in the direction of powers which are not yet fully revealed to him.

At times, it appears to him as if the task were hopeless of establishing any harmony between his own nature and the nature of things.

Now he is filled with an exhilarating confidence in his own gifts and in his destiny to bring them to full fruition; now he seems to be paralysed with a sense of impotence in which we see all the perils attending his peculiar temperament.

In his letters to his Strassburg friend Salzmann we have the frankest communications regarding his alternating moods of depression and hopefulness.

"What I am doing," he writes immediately after his settlement in Frankfort, "is of no account.