Yoko Ono: If the mantra itself has such power, does it matter where you receive it, where you take it?
Prabhupāda: Yes. Yes. That is a fact. The example is given just like milk. Milk is nutritious. That's a fact. Everyone knows. But if the milk is touched through the tongue of a serpent, it is no more nutritious. It is poison.
Yoko Ono: Well, milk is material.
Prabhupāda: No, material. You want to understand through your material senses, we have to give...
Yoko Ono: Well, no. I don't have, you don't have to tell me material senses. I mean mantra is not material. It should be something spiritual, and therefore nobody can spoil it, I don't think. I mean, I wonder if anybody can spoil something that is not material.
Prabhupāda: But the thing is that if you don't receive the mantra through the proper channel, it may not be mantra.
John Lennon: But how would you know, anyway? How are you able to tell, anyway? I mean, for any of your disciples or us or anybody that goes to any spiritual master, how are we to tell...
Prabhupāda: Not any spiritual master.
John Lennon: True master. How are we to tell one from the other?
Prabhupāda: It is not that any spiritual master. Sampradāya. Sampradāya means a particular line of disciplic succession.