Once Srila Prabhupada was walking with Hari-vilasa prabhu in France, explaining how important it was for his scientists to explain things in a scientific way. He said that if he (Srila Prabhupada) said such things, people would take him as a crazy old man. Hari-vilasa said that because Srila Prabhupada was so CONVINCED about the structure of the universe, the temporary nature of material existence, and the eternality of the soul, that it would be hard not accept these principles as facts of life.