Now these ancient thinkers of India applied this law of Karma to explain the destiny of human souls, and it was upon this law they based the theory of Transmigration. They maintained that human souls are bound by this irresistible law and cannot get out of it; their thoughts and deeds are the causes which produce results of similar nature. So their future birth does not depend upon their whimsical, free choice, but it is limited by the thoughts and deeds or misdeeds of their previous lives. In the Platonic idea we find that the souls go according to their choice. They may not take a human form if they prefer an animal form, but in the Hindu idea of transmigration we find that it is not a result of free choice, but, if our thoughts and deeds force us to take a particular form, then we are subject to the law of Karma, which governs our future birth and the evolution of our souls. Consequently the Hindu theory of Transmigration differs fundamentally from the Platonic as well as from the Egyptian idea of Transmigration. In the Platonic and Egyptian theories we see that the souls, after leaving the body, enter into another body which is waiting to receive the migrating soul, but in the Hindu theory of Transmigration the body is not waiting to receive the migrating soul, but on the contrary the soul, being subject to the laws of evolution, manufactures the gross material body according to its desires and tendencies. Just as a germ of life will develop a grosser form by cellular subdivision, by growth, and by assimilation of the environmental conditions, so the germ of the human soul will manufacture the body by obeying the laws which govern the physical plane. Parents are nothing but the channels through which the migrating souls receive their material forms. Parents do not create the souls; they have no power to create. They can only give the suitable environments necessary for manufacturing a gross physical body. The souls come with their tendencies, with their desires, and they remain as germs of life.