Class continued with Madhya-lila 20.106. Prabhupada explained that human life begins when we can distinguish between sat [reality] and asat [illusion]. "If we remain in darkness without understanding what is sat and asat then we are no better than dogs and cats. So the modern civilization, not only nowadays very big problem, people are very much attached to asat-dharma. Because they are so dull-headed, they cannot understand what is sat and what is asat.
Therefore brain requires to be clarified. The two words are used in the sastra, alpa-medhasah. Medhas means brain substance. So those who have got brain substance, they are called su-medhasah; and those who have no brain substance, filled up with cow dung, they are called alpa-medhasah." Aware that using such strong words is not always agreeable to the materially attached persons, Srila Prabhupada recalled his visit to America last year. "This is distinction I made in Chicago. It made a very great agitation because I discriminated that men are found to have more brain substance than the woman. So there was a great agitation. But this is fact psychologically that brain substance in man is greater than the brain substance in a woman.
But in spiritual understanding there is no such distinction because sat-dharma, spiritual understanding, has nothing to do with this body. The brain substance more or less is in connection with body; but the sat, the spirit soul, it has nothing to do with the body. So long it has to do something with the body, that is called maya. He's sat, but he is absorbed in the thought of asat. That is called maya, what he is not."