This is a lecture from the book Caitanya-caritāmṛta, Madhya-līlā 20.98-99 that Srila Prabhupada gave on July 4, 1974 in Washington, D.C..
So what is our real interest? By evolutionary process, after going through so many forms of life, jalajā nava-lakṣāṇi sthāvarā lakṣa-viṁśati kṛmayo rudra-saṅkhyakāḥ, in this way, eight million forms of life, and we have got this human form of life. So this life especially meant for athāto brahma jijnāsā. Simply to understand our spiritual identity, the Absolute Truth, that is the only business. But we are... We have got the intelligence more than the cats and dogs. They cannot inquire about the spiritual identity, and if we keep ourself in darkness without understanding our spiritual identity, then we are no better than the dogs and cats. Therefore he said, nīca jāti: "I have no information about the soul." Nīca jāti.
Just like dogs. It is a class. So nīca. Of course, in your country dog is very pet. Now we are learning also, India, how to keep a dog and become aristocratic. (laughter) So now there is big, big dog show in New Delhi. But actually in India, although dog was not neglected, in a neighborhood, if there is a dog, people will give him food but not allow to enter into the house. He'll be not allowed. A dog is also trained up. They'll come to a door and sit down and move his tail: "Give me some food." And people will give. But he's not allowed to enter, the dog or caṇḍālas are not allowed.