There is another group of principles that, for several reasons, can be placed under the broad heading of Desires, though they are clearly different in some ways from that form of desire known as the appetites.These principles, which are called the Propensities or Propensive principles in order to distinguish them from the appetites, seem to depend less on the condition of the physical body for their existence and activity than the appetites do. These are what we commonly call
inclinations. Since they are, to some extent, removed from the outward senses, which form the basis for the action of the appetites, they plainly stand closer to the higher and more important principles of our nature. For that reason, in the usual way we judge the different parts of our mental constitution, they are seen as holding a higher rank. Some of the principles that belong under this general heading — for it is not necessary to list them all, and even less necessary to examine them one by one — are the principle of self-preservation, or the desire for continued existence; curiosity, or the desire for knowledge; sociality, or the desire for society; self-love, or the desire for happiness; the desire for esteem; and several others.
