On December 11, 1971 in New Delhi, AC Bhaktivedanta criticized materialistic persons’ imperfect vision and speculative theories. He argued that imperfect senses cannot lead to perfect knowledge, challenging astronomers and scientists. He described different types of conditioned souls – good, passionate, and rascal. He also criticized Vivekananda and Karpatri for their imperfect conclusions despite their knowledge. Bhakti-yoga, according to him, cleanses the mind and intelligence, allowing one to see the Supreme Personality of Godhead and maya. He emphasized the power of bhakti-yoga in revealing all knowledge.