And then there comes the next stage of knowing oneself, and that is to explore what one calls the mind. By a minute study of the mind one will find that the different qualities such as reason, memory, thought, feeling, and the ego, all these five things constitute mind. One will find that there is a surface to this and there is a depth to it. Its depth is the heart; its surface is mind. Each quality of mind represents one of these five elements. This again takes us to the thought that even the mind, which is above the physical body, is a mechanism. And the more one is acquainted with the mechanism, the more one is able to manage it to its best advantage; and it is the ignorance of the secret of this mechanism that keeps man unaware of his own domain.