Sattvam visuddham vasudeva-sabditam (Bhag. 4.3.23). In this material world, the three modes of material naturegoodness, passion and ignoranceprevail. Among these three, goodness is the platform of knowledge, and passion brings about a mixture of knowledge and ignorance, but the mode of ignorance is full of darkness. Therefore the Supreme Personality of Godhead is beyond darkness and passion. He is on the platform where goodness or knowledge is not disturbed by passion and ignorance. This is called the vasudeva platform. It is on this platform of vasudeva that Vasudeva, or Krsna, can appear. Thus Krsna appeared on this planet as the son of Vasudeva. Because the Lord is situated beyond the three modes of material nature, He is unseen by those who are dominated by these three modes. One must therefore become dhira, or undisturbed by the modes of material nature. The process of yoga may be practiced by one who is free from the agitation of these modes. Therefore yoga is defined in this way: yoga indriya-samyamah. As previously explained, we are disturbed by the indriyas, or senses. Moreover, we are agitated by the three modes of material nature, which are imposed upon us by the external energy. In conditional life, the living entity moves turbulently in the whirlpool of birth and death, but when one is situated on the transcendental platform of visuddha-sattva, pure goodness, he can see the Supreme Personality of Godhead, who sits on the back of Garuda. Lord Brahma offers his respectful obeisances unto that Supreme Lord.