Because you are human beings, you are together here to get this knowledge. The cats and dogs cannot come. They cannot take this knowledge. So we have got the advantage of getting this knowledge in this life, and again, if we go back to the cats' and dogs' knowledge, then what is the benefit of getting this body? So this civilization, this dog civilization, is so spread all over the world that it is very, very difficult to cure it. We are making little attempt, but the ignorance is so deep, the disease is so acute, it is very, very difficult.

From Srila Prabhupada's talk on Bhagavad-gita 16.1-3  — January 29, 1975, Honolulu