Hayagrīva: Concerning remembering and forgetting, Bergson writes, "The cerebral mechanism is arranged just so as to drive back into the unconscious"—by unconscious they mean the subconscious—"almost the whole of his past, and to admit beyond the threshold only that which can cast light on the present situation or further the action now being prepared. In short, only that which can give useful work." So that, in other words, man utilizes only those memories or that knowledge which is immediately useful, and in this way man can function in the world. What is the role of Kṛṣṇa in this, as the arranger of this cerebral mechanism?
Prabhupāda: Cerebral mechanism, that is a machine. Just like this microphone is a machine. It helps speaking loudly. It has nothing..., machine has nothing to do with the voice, but it helps the voice louder so we can listen, so far the machine is concerned. Actually the voice is different. Therefore our Vedic śāstra is called voice, śruti. So if the śruti, the voice, vibration of this voice is proper, then the machine can help us to understand that. But if there is no voice, what is the use of the machine? Just like dead body: the same brain is there, what is the use? The same ear is there. So it is not the brain that helps; it is the voice, it is the instruction which helps.