em; 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, I shall
decline, as lying out of my way in the design I am now upon. It shall
suffice to my present purpose, to consider the discerning faculties of a
man, as they are employed about the objects which they have to do with.
And I shall imagine I have not wholly misemployed myself in the thoughts
I shall have on this occasion, if, in this historical, plain method,
I can give any account of the ways whereby our understandings come to
attain those notions of things we have; and can set down any measures
of the certainty of our knowledge; or the grounds of those persuasions
which are to be found amongst men, so various, different, and wholly
contradictory; and yet asserted somewhere or other with such assurance
and confidence, that he that shall take a view of the opinions of
mankind, observe their opposition, and at the same time consider the
fondness and devotion wherewith they are embraced, the resolution and
eagerness wherewith they are maintained, may perhaps have reason to
suspect, that either there is no such thing as truth at all, or that
mankind hath no sufficient means to attain a certain knowledge of it.

3. Method.

It is therefore worth while