at least, if mine prove a castle in the air, I will endeavour it shall be all of a piece and hang together.  Wherein I warn the reader not to expect undeniable cogent demonstrations, unless I may be allowed the privilege, not seldom assumed by others, to take my principles for granted; and then, I doubt not, but I can demonstrate too.  All that I shall say for the principles I proceed on is, that I can only appeal to men’s own unprejudiced experience and observation whether they be true or not; and this is enough for a man who professes no more than to lay down candidly and freely his own conjectures, concerning a subject lying somewhat in the dark, without any other design than an unbiassed inquiry after truth.

BOOK II

OF IDEAS

CHAPTER I.

Of ideas in general, and their original.

1.  Idea is the Object of Thinking.

Every man being conscious to himself that he thinks; and that which his mind is applied about whilst thinking being the ideas that are there, it is past doubt that men have in their minds several ideas,—­such as are those expressed by the words whiteness, hardness, sweetness, thinking, motion, man, elephant, army, drunkenness, and others:  it is in the first place then to be inquired, how he comes by them?

I know it is a received doctrine, that men have native ideas, and original characters, stamped upon their minds in their very first being.  This opinion I have at large examined already; and, I suppose what I have said in the foregoing Book will be much more easily admitted, when I have shown whence the understanding may get all the ideas it has; and by what ways and degrees they may come into the mind;—­for which I shall appeal to every one’s own observation and experience.

2.  All Ideas come from Sensation or Reflection.

Let us then suppose the mind to be, as we say, white paper, void of all characters, without any ideas:—­How comes it to be furnished?  Whence comes it by that vast store which the busy and boundless fancy of man has painted on it with an almost endless variety?  Whence has it all the materials of reason and knowledge?  To this I answer, in one word, from experience.  In that all our knowledge is founded; and from that it ultimately derives itself.  Our observation employed either, about external sensible objects, or about the internal operations of our minds perceived and reflected on by ourselves, is that which supplies our understandings with all the materials of thinking.  These two are the fountains of knowledge, from whence all the ideas we have, or can naturally have, do spring.

3.  The Objects of Sensation one Source of Ideas