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.
John Lennon: But, you see, Maharishi said exactly the same thing about his mantra's coming from the Vedic, with seemingly as much authority as you, and he was probably right. So how... It's like having too many fruits on a plate, and you can't only eat two of them.
Prabhupāda: No. If mantra is coming down in that way, then it is potency; the potency is there.
John Lennon: But Hare Kṛṣṇa is the best one.
Prabhupāda: Yes.
Yoko Ono: Well, if Hare Kṛṣṇa is the best one, what is the reason why we have to bother to even say anything else other than this one?
Prabhupāda: You don't require to bother to say anything else. We say that Hare Kṛṣṇa mantra is sufficient for one's perfection.