There are four different ways by which one can attain to the knowledge of this truth.

1. One person has been told that self-knowledge is the guide to perfection, and he says, "Yes, it must be so." He knows no more than that.
2. There is another person who has read in this or in that book that it is self-knowledge which leads to perfection; and he thinks it must be true because it is written in a book.
3. There is a third person who has reasoned it out; and by his reasoning, by synthesizing, he comes to the knowledge that it is one which has become many, that this variety is again gathered into one, and that this one is to be found in oneself. No doubt the more his reason helps him, the more he will be consoled.
4. But then there is a fourth person who realizes this truth himself, not by reason but by experience, and that is the way of the mystic.