Secondly, Because observing the faculties of the mind, how they operate about simple ideas,—which are usually, in most men’s minds, much more clear, precise, and distinct than complex ones,—we may the better examine and learn how the mind extracts, denominates, compares, and exercises, in its other operations about those which are complex, wherein we are much more liable to mistake. Thirdly, Because these very operations of the mind about ideas received from sensations, are themselves, when reflected on, another set of ideas, derived from that other source of our knowledge, which I call reflection; and therefore fit to be considered in this place after the simple ideas of sensation. Of compounding, comparing, abstracting, &c., I have but just spoken, having occasion to treat of them more at large in other places. 15. The true Beginning of Human Knowledge. And thus I have given a short, and, I think, true HISTORY OF THE FIRST BEGINNINGS OF HUMAN KNOWLEDGE;—whence the mind has its first objects; and by what steps it makes its progress to the laying in and storing up those ideas, out of which is to be framed all the knowledge it is capable of: wherein I must appeal to experience and observation whether I am in the right: the best way to come to truth being to examine things as really they are, and not to conclude they are, as we fancy of ourselves, or have been taught by others to imagine. 16. Appeal to Experience. To deal truly, this is the only way that I can discover, whereby the IDEAS OF THINGS are brought into the understanding. If other men have either innate ideas or infused principles, they have reason to enjoy them; and if they are sure of it, it is impossible for others to deny them the privilege that they have above their neighbours. I can speak but of what I find in myself, and is agreeable to those notions, which, if we will examine the whole course of men in their several ages, countries, and educations, seem to depend on those foundations which I have laid, and to correspond with this method in all the parts and degrees thereof. 17. Dark Room. I pretend not to teach, but to inquire; and therefore cannot but confess here again,—that external and internal sensation are the only passages 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 openings left, to let in external visible resemblances, or ideas of things without: which, would they 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. These are my guesses concerning the means whereby the understanding comes to have and retain simple ideas, and the modes of them, with some other operations about them.