Anyone who is a not a Vaisnava, or an unalloyed devotee of the Supreme Lord, must be a materialist. A Vaisnava living according to Sri Caitanya Mahaprabhu's injunctions is certainly not on the materialistic platform. Caitanya means "spiritual force." All of Sri Caitanya Mahaprabhu's activities were carried out on the platform of spiritual understanding; therefore only those who are on the spiritual platform are able to understand the activities of Sri Caitanya Mahaprabhu. Materialistic persons who cannot are generally known as karmis or jnanis. The jnanis are mental speculators who simply try to understand what is spirit and what is soul. Their process is neti neti: "This is not spirit, this is not Brahman." The jnanis are a little more advanced than the dull-headed karmis, who are simply interested in sense gratification. Before becoming a Vaisnava, Sarvabhauma Bhattacarya was a mental speculator (jnani), and being such, he always cut jokes with Vaisnavas. A Vaisnava never agrees with the speculative system of the jnanis. Both the jnanis and karmis depend on direct sense perception for their imperfect knowledge. The karmis never agree to accept anything not directly perceived, and the jnanis put forth only hypotheses. However, the Vaisnavas, the unalloyed devotees of the Lord, do not follow the process of acquiring knowledge by direct sense perception or mental speculation. Because they are servants of the Supreme Lord, devotees receive knowledge directly from the Supreme Personality of Godhead as He speaks it in the Bhagavad-gita, or sometimes as He imparts it from within as the caitya-guru. As stated in the Bhagavad-gita (10.10):

"To those who are constantly devoted to serving Me with love, I give the understanding by which they can come to Me." (Bg. 10.10)