for.  I have made choice of these terms to signify, (1) Some immediate object of the mind, which it perceives and has before it, distinct from the sound it uses as a sign of it. (2) That this idea, thus determined, i.e. which the mind has in itself, and knows, and sees there, be determined without any change to that name, and that name determined to that precise idea.  If men had such determined ideas in their inquiries and discourses, they would both discern how far their own inquiries and discourses went, and avoid the greatest part of the disputes and wranglings they have with others.

Besides this, the bookseller will think it necessary I should advertise the reader that there is an addition of two chapters wholly new; the one of the Association of Ideas, the other of Enthusiasm.  These, with some other larger additions never before printed, he has engaged to print by themselves, after the same manner, and for the same purpose, as was done when this Essay had the second impression.

In the Sixth Edition there is very little added or altered.  The greatest part of what is new is contained in the twenty-first chapter of the second book, which any one, if he thinks it worth while, may, with a very little labour, transcribe into the margin of the former edition.

ESSAY CONCERNING HUMAN UNDERSTANDING.

INTRODUCTION.

1.  An Inquiry into the Understanding pleasant and useful.

Since it is the understanding that sets man above the rest of sensible beings, and gives him all the advantage and dominion which he has over them; it is certainly a subject, even for its nobleness, worth our labour to inquire into.  The understanding, like the eye, whilst it makes us see and perceive all other things, takes no notice of itself; and it requires and art and pains to set it at a distance and make it its own object.  But whatever be the difficulties that lie in the way of this inquiry; whatever it be that keeps us so much in the dark to ourselves; sure I am that all the light we can let in upon our minds, all the acquaintance we can make with our own understandings, will not only be very pleasant, but bring us great advantage, in directing our thoughts in the search of other things.

2.  Design.

This, therefore, being my purpose—­to inquire into the original, certainty, and extent of human knowledge, together with the grounds and degrees of belief, opinion, and assent;—­I shall not at present meddle with the physical consideration of the mind; or trouble myself to examine wherein its essence consists; or by what motions of our spirits or alterations of our bodies we come to have any sensation by our organs, or any ideas in our understandings; and whether those ideas do in their formation, any or all of them, depend on matter or not.  These are speculations which, however curious and entertaining,