‘Secondly, the other fountain from whence experience furnisheth the understanding with ideas, is the perception of the operations of our own mind within us, as it is employed about the ideas it has got: which operations when the soul comes to reflect on and consider, do furnish the understanding with another set of ideas, which could not be had from things without: and such are _perception_, _thinking_, _doubting_, _believing_, _reasoning_, _knowing_, _willing_, and all the different actings of our own minds; which we being conscious of, and observing in ourselves, do from these receive into our understandings as distinct ideas as we do from bodies affecting our senses. This source of ideas every man has wholly in himself; and though it be not sense, as having nothing to do with external objects, yet it is very like it, and might properly enough be called internal sense. But as I call the other sensation, so I call this REFLECTION; the ideas it affords being such only as the mind gets by reflecting on its own operations within itself.... These two I say, _viz._ external, material things, as the objects of sensation, and the operations of our own minds within as the objects of REFLECTION, are to me the only originals from whence all our ideas take their beginnings. The term _operations_ here I use in a large sense, as comprehending not barely the actions of the mind about its ideas, but some sort of passions arising sometimes from them, such as is the satisfaction or uneasiness arising from any thought.’ ‘The understanding,’ proceeds Mr. Locke, ‘seems to me not to have the least glimmering of any ideas, which it doth not receive from one of these two. External objects furnish the mind with the ideas of sensible qualities, which are all those different perceptions they produce in us; and the mind furnishes the understanding with ideas of its own operations. These, when we have taken a full survey of them, and their several modes, combinations, and relations, we shall find to contain all our whole stock of ideas: and that we have nothing in our minds, which did not come in one of these two ways.’—_Essay_, vol. I. p. 84. Again, page 150, he says: ‘I pretend not to teach but to inquire, and therefore cannot but confess here again, that external and internal sensation are the only passages that I can find of knowledge to the understanding. These alone, as far as I can discover, are the windows by which light is let into this dark room. For methinks the understanding is not much unlike a closet, wholly shut from light, with only some little opening left, to let in external visible resemblances, or ideas of things without: would the pictures coming into such a dark room but stay there, and lie so orderly as to be found upon occasion, it would very much resemble the understanding of a man in reference to all objects of sight, and the ideas of them.’