As already explained, there are three prasthanas on the path of advancement in spiritual knowledge-namely, nyaya-prasthana (Vedanta philosophy), sruti-prasthana (the Upanisads and Vedic mantras) and smrti-prasthana (the Bhagavad-gita, Mahabharata, Puranas, etc.). Unfortunately, Mayavadi philosophers do not accept the smrti-prasthana. Smrti refers to the conclusions drawn from the Vedic evidence. Sometimes Mayavadi philosophers do not accept the authority of the Bhagavad-gita and the Puranas, and this is called ardha-kukkuti-nyaya, "the logic of half a hen." (A foolish farmer once thought he would save money by cutting off his hen's head, which he had to feed, and leaving its tail, which produced the eggs.) If one believes in the Vedic literature, one must accept all the Vedic scriptures recognized by the great acaryas, but these Mayavadi philosophers accept only the nyaya-prasthana and sruti-prasthana, rejecting the smrti-prasthana. Here, however, Sri Caitanya Mahaprabhu cites evidence from the Gita, Visnu Purana, etc., which are smrti-prasthana. No one can avoid the Personality of Godhead in the statements of the Bhagavad-gita and other Vedic scripttures such as the Mahabharata and the Puranas. Lord Caitanya therefore quotes a passage from the Bhagavad-gita (7.5).