Devotee: Srila Prabhupada, because you are presenting this knowledge so purely, then it’s possible for the common man to understand this knowledge without chanting and following the four regulative principles.

Prabhupada: That is not possible. That is not possible. Ceto-darpaNa-mArjanam [Cc. Antya 20.12]. You have to cleanse the mirror of your consciousness, then the reflection will be properly viewed. If you keep it dirty, then it is not possible. Therefore we require first-class men to understand this philosophy, not the fourth-class man. If you keep him fourth-class man, it is not possible.

Excerpt from July 5 1975, Room Conversations