This is the secret-most knowledge. Now another type of meditation is described. After having contemplated as before on the excellent lotus in the heart, the Atman should be thought of as a doer,^ with the lustre equal to that of fire. In ■the middle of that lotus, Purusa, the twentyfifth principle should be thought of as being of the form of the flame of fire. 62-63, He should meditate upon the supreme Atman in its middle—^The Paramatman as the supreme firmament, the principle expressed by Oihkara and called eternal, auspicious, the unmanifest, latent in Prakrti and the supreme light, the inner highest principle, the basis of Atman and unsullied.