When the understanding is once stored with these simple ideas, it has the power to repeat, compare, and unite them even to an almost infinite variety, and so can make at will new complex ideas. But it is not in the power of any most exalted wit or enlarged understanding, by any quickness or variety of thought, to invent or frame one new simple idea in the mind, nor to destroy those that are there. I would have anyone try to fancy any taste which had never affected his palate, or frame the idea of a scent he had never smelt; and when he can do this, I will also conclude that a blind man hath ideas of colours and a deaf man true, distinct notions of sound. There are some ideas which have admittance only through one sense which is peculiarly adapted to receive them. Thus, light and colours come in only by the eye, all kinds of noises by the ear, the tastes and smells by the nose and palate. The most considerable of those belonging to the touch are heat, cold, and solidity--which is the idea that belongs to the body, whereby we conceive it to fill space. Simple ideas of divers senses are the ideas of space or extension, figure, rest, and motion, for these make perceivable impressions both on the eyes and touch, and we can receive and convey into our minds the ideas of the extension, figure, motion, and rest of bodies both by seeing and feeling. The mind, receiving the ideas mentioned in the foregoing from without, when it turns its view inward upon itself and observes its own actions about those ideas it has, takes from thence other ideas which are as capable to be the objects of its contemplation as any of those it received from foreign things. The two great and principal actions of the mind which are most frequently considered, and which are so frequent that everyone that pleases may take notice of them in himself, are these two--Perception or Thinking, and Volition or Will. The power of thinking is called the Understanding, and the power of volition is called the Will. And these two powers, or abilities, in the mind are denominated Faculties. Some of the modes of these simple ideas of reflection are remembrance, discerning, reasoning, judging, knowledge, faith. It has, further, pleased our wise Creator to annex to several objects and to the ideas which we receive from them, as also to several of our thoughts, a concomitant pleasure, and that in several objects to several degrees, that those faculties which He has endowed us with might not remain wholly idle and unemployed by us. Pain has the same efficacy and use to set us on work that pleasure has, we being as ready to employ our faculties to avoid that as to pursue this. Existence and unity are two other ideas that are suggested to the understanding by every object without and every idea within. Power, also, is another of those simple ideas which we receive from sensation and reflection; and, besides these, there is succession.