-Swami Vivekananda

The main difference between men and the animals is the difference in their power of concentration. All success in any line of work is the result of this. Everybody knows something about concentration. We see its results every day. High achievements in art, music, etc. are the results of concentration.

An animal has very little power of concentration. Those who have trained animals find much difficulty in the fact that the animal is constantly forgetting what is told him. He cannot concentrate his mind long upon anything at a time. Herein is the difference between man and the animals—man has the greater power of concentration.

The difference in their power of concentration also constitutes the difference between man and man. Compare the lowest with the highest man. The difference is in the degree of concentration. This is the only difference.

The mind-stuff is a very fine material instrument used for taking up the Prana. When a man dies, the body dies; but a little bit of the mind, the seed, is left when all else is shattered; and this is the seed of the new body called by St. Paul “the spiritual body”. This theory of the materiality of the mind accords with all modern theories.

The idiot is lacking in intelligence because his mind-stuff is injured. Intelligence cannot be in matter nor can it be produced by any combinations of matter. Where then is intelligence? It is behind matter; it is the Jiva, the real Self, working through the instrument of matter. Transmission of force is not possible without matter, and as the Jiva cannot travel alone, some part of mind is left as a transmitting medium when all else is shattered by death.