Prabhupāda: We read one story. One little boy, he was beating on a drum. So he became inquisitive, "Wherefrom the sound is coming? Somebody must be within it." So he took a knife and cut it. This is intelligence: "Wherefrom the sound is coming?" He was beating—dum, dum, dum—he became inquisitive. That is intelligence. A dull student—coming, that's all. And intelligent, he tries to . . . that is intelligence. Inquisitiveness. Intelligent boy will always enquire, "What is this, father? What is this, father? Wherefrom the sound is coming?" That is intelligence. So if one is very dull—just like cats and dogs, they cannot enquire, "What is this machine? What is this behind?" It is in the human form of life these enquiries should come. Otherwise he remains a cat and dog.
Jayadharma: They say that they don't accept this body as a machine because they've never experienced a machine that can think, feel and will for itself.
Prabhupāda: What is that?
Paramahaṁsa: Well, they say that this body is more complicated than any other machine because it can think, feel and will, whereas other machines, they don't do that.
Prabhupāda: But the thinking, feeling, the brain is there. If the . . . that is the particular machine, because the operator is within. That you cannot see. The thinking, feeling is coming from the operator. The soul is there, dehino 'smin yatha dehe (BG 2.13). That these rascals cannot understand, that the thinking, feeling, that is of the operator, not of the machine. Is it clear or not? The operator is within. So the thinking, feeling, as you were asking, that is not of the machine but of the operator, the soul.