Prabhupāda: . . . the existence of God. There must be. How can you deny existence of God? It is not possible. Now, if you are convinced that there is God, then the next question will be, "What is that God? Is He a living being or a stone? What is the nature of God or the features of God? Whether He has . . ." So many things we have to study about. But first of all we have to accept there is God. God, what kind of thing is that God, that is called brahma-jijñāsā. That is the beginning of philosophy. Athāto brahma jijñāsā. That what is God, what is His nature, what is His feature, what does He do—these things can be inquired by human being. A dog cannot inquire. So if a human being is not interested in these things, he's a dog. Do you agree or not? If a human being is not interested to know about God, then he's dog. This is our first charge. Now let the agnostic refute. Hmm? In human life . . . there are varieties of living entities, so many. The trees are also living entities, but it is standing; it has no other capacity. The birds are there, they're little improved, they're flying, they can move from one tree to another, but they have no capacity to inquire about God. There are so many insects, they are also living entity, but they do not inquire about God. It is only human being, he can inquire about. That particular facility is given.
Shahrezad (an Iranian lady): Why . . .
Prabhupāda: Because it is necessary.
Shahrezad: No, I mean the difference between human being and the animals.
Prabhupāda: Huh? What . . .
Devotee: The difference between human being and the animals.
Harikeśa: Why is that?
Prabhupāda: No, the first thing is that we have to accept there is God. Now, to inquire about God, this facility is given to the human being. So you must utilize it. Otherwise you are not human. Your business is, by nature's creation, your business is. The human being . . . just like you dress yourself nicely, you comb your hair. That is possible by the human being. An animal may have big hair, but it cannot dress because he has no intelligence. So if you have got intelligence, if you utilize it, then life's profit is there. If you don't utilize it, then you remain lower-grade animal. So in the human form of life, the preliminary is that he can inquire about God, he can understand about God. So if he does not utilize his life for that purpose, then he is animal.