Every voluntary or involuntary action of the body, sense or mind must correspond to the dormant impressions stored up in the subtle body. Although growth, the process of nourishment and all the changes of the gross physical body take place according to the necessarily acting causes, yet the whole series of actions, and consequently every individual act, the condition of the body which accomplishes it, nay, the whole process in and through which the body exists, are nothing but the outward expressions of the latent impressions stored up in the subtle body. Upon these rests the perfect suitableness of the animal or human body to the animal or human nature of one's impressions. The organs of the senses must therefore completely correspond to the principal desires which are the strongest and most ready to manifest. They are the visible expressions of these desires. If there be no hunger or desire to eat, teeth, throat and bowels will be of no use. If there be no desire for grasping and moving, hands and legs will be useless. Similarly it can be shown that the desire for seeing, hearing, etc., has produced the eye, ear, etc. If I have no desire to use my hand, and if I do not use it at all, within a few months it will wither away and die. In India there are some religious fanatics who hold up their arms and do not use them at all; after a few months their arms wither and become stiff and dead. A person who lies on his back for six months loses the power of walking. There are many such instances which prove the injurious effects of the disuse of our limbs and organs.