Just like a tiger grows the tiger body, a man grows a man's body, the hog grows the hog's body. The body is grown in the mother's body, and when it is complete it comes out and becomes this body.
Therefore this human form of life is a chance to understand his real position. In other lives other than human form of life, they are coming by nature's law, by evolution, transmigration—evolution, Darwin's theory of evolution. But the process of evolution are just like there is evolution in human life. There are 4,000 species of human life. They are 8,400,000 species of different forms of life, so other than human beings, there are 8,000,000 forms, and in the human form of life there are 4,000 human species of life. Therefore we find so many varieties; the two bodies will never coincide exactly, the different forms of life.
So when one comes to the human form of life, never mind whether he is highly advanced civilized life or uncivilized life, the human form life has got a special privilege to understand his position. It doesn't matter whether he is European or American or Indian or brahmin or śūdra—these are of course bodily differentiation—but the human consciousness is there. Therefore if we utilize this human consciousness and try to understand our constitutional position, "What I am?" and if I can understand that I am spirit soul, part and parcel of God, then my life is perfect.