Why therefore should we recognize two kinds of desires, instead of acknowledging only one kind in the living body? Because nature differs from the body to which it gives life. Nature is anterior to the body because it is nature that organizes the body by moulding it, and shaping it; consequently, the origin of desire is not in nature, but in the passions of the living body. If the latter suffer, it aspires to possess things contrary to those that make it suffer, to make pleasure succeed pain, and satisfaction succeed need. Nature, like a mother, guesses the desires of the body that has suffered, tries to direct it, and to lure it back. While thus trying to satisfy it, she thereby shares in its desires, and she proposes to accomplish the same ends. It might be said that the body, by itself, possesses desires and inclinations; that nature has some only as a result of the body, and because of it; that, finally the soul is an independent power which grants or refuses what is desired by the organism. DESIRES ARE PHYSICAL, BECAUSE CHANGEABLE IN HARMONY WITH THE BODY. 21. The observation of the different ages shows that it is indeed the organism which is the origin of desires. Indeed, these change according as the man is a child or a youth, sick or well. Nevertheless that part of the soul which is the seat of desires ever remains the same. Consequently the variations of desire must be traced back to the variations of the organism. But this desiring faculty of the soul is not always entirely wakened by the excitation of the body, although this subsists to the end. Often even before having deliberated, the soul will forbid the body to drink or eat, although the organism desires it as keenly as possible. Nature herself also often forbids the satisfaction of the bodily desire, because such desire may not seem to it natural, and because she alone has the right to decide what things are harmonious to or contrary to nature. The theory that the body, by its different states suggests different desires to the soul's faculty of desire, does not explain how the different states of the body can inspire different desires in the soul's faculty of desire, since then it is not itself that it seeks to satisfy. For it is not for itself, but for the organism, that the soul's faculty of desire seeks foods, humidity or heat, motion, agitation, or the satisfaction of hunger. RELATION OF DESIRE-FUNCTION TO THE VEGETATIVE POWERS. 22. It is possible, even in plant-life, to distinguish something which is the characteristic property of their bodies, and a power that imparts it to them. What in us in the soul's faculty of desire, is in plant-life the natural element (or, vegetative power). PLATO IS IN DOUBT ABOUT THE EARTH'S SOUL; WHETHER SHE IS LIKE THOSE OF STARS.