If any one asks me, WHAT THIS SOLIDITY IS, I send him to his senses to inform him. Let him put a flint or a football between his hands, and then endeavour to join them, and he will know. If he thinks this not a sufficient explication of solidity, what it is, and wherein it consists; I promise to tell him what it is, and wherein it consists, when he tells me what thinking is, or wherein it consists; or explains to me what extension or motion is, which perhaps seems much easier. The simple ideas we have, are such as experience teaches them us; but if, beyond that, we endeavour by words to make them clearer in the mind, we shall succeed no better than if we went about to clear up the darkness of a blind man’s mind by talking; and to discourse into him the ideas of light and colours. The reason of this I shall show in another place.
CHAPTER V.
OF SIMPLE IDEAS OF DIVERS SENSES.
Ideas received both by seeing and touching.
The ideas we get by more than one sense are, 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. But having occasion to speak more at large of these in another place, I here only enumerate them.
CHAPTER VI.
OF SIMPLE IDEAS OF REFLECTION.
Simple Ideas are the Operations of Mind about its other Ideas.
The mind receiving the ideas mentioned in the foregoing chapters 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 Idea of Perception, and Idea of Willing, we have from Reflection.