We gain all our knowledge through experience; that is the only way. What we call experiences are on the plane of consciousness. For illustration: A man plays a tune on a piano, he places each finger on each key consciously. He repeats this process till the movement of the fingers becomes a habit. He then plays a tune without having to pay special attention to each particular key. Similarly, we find in regard to ourselves that our tendencies are the result of past conscious actions. A child is born with certain tendencies. Whence do they come? No child is born with a tabula rasa— with a clean, blank page — of a mind.
The page has been written on previously. The old Greek and Egyptian philosophers taught that no child came with a vacant mind. Each child comes with a hundred tendencies generated by past conscious actions. It did not acquire these in this life, and we are bound to admit that it must have had them in past lives. The rankest materialist has to admit that these tendencies are the result of past actions, only they add that these tendencies come through heredity. Our parents, grandparents, and great-grandparents come down to us through this law of heredity. Now if heredity alone explains this, there is no necessity of believing in the soul at all, because body explains everything. We need not go into the different arguments and discussions on materialism and spiritualism. So far the way is clear for those who believe in an individual soul. We see that to come to a reasonable conclusion we must admit that we have had past lives. This is the belief of the great philosophers and sages of the past and of modern times. (I, 320 – 321)