here is the head that has no chimeras in
it? Or if there be a sober and a wise man, what difference will
there be, by your rules, between his knowledge and that of the most
extravagant fancy in the world? They both have their ideas, and perceive
their agreement and disagreement one with another. If there be any
difference between them, the advantage will be on the warm-headed man's
side, as having the more ideas, and the more lively. And so, by your
rules, he will be the more knowing. If it be true, that all knowledge
lies only in the perception of the agreement or disagreement of our own
ideas, the visions of an enthusiast and the reasonings of a sober man
will be equally certain. It is no matter how things are: so a man
observe but the agreement of his own imaginations, and talk conformably,
it is all truth, all certainty. Such castles in the air will be as
strongholds of truth, as the demonstrations of Euclid. That an harpy is
not a centaur is by this way as certain knowledge, and as much a truth,
as that a square is not a circle.

'But of what use is all this fine knowledge of MEN'S OWN IMAGINATIONS,
to a man that inquires after the reality of things? It matters not what
men's fancies are, it is the knowledge of things that is only to be
prized: it is this alone gives a value to our reasonings, and preference
to one man's knowledge over another's, that it is of things as they
really are, and not of dreams and fancies.'

2. Answer Not so, where Ideas agree with Things.

To which I answer, That if our knowledge of our ideas terminate in them,
and reach no further, where there is something further intended, our
most serious thoughts will be of little more use than the reveries of
a crazy brain; and the truths built thereon of no more weight than the
discourses of a man who sees things clearly in a dream, and with great
assurance utters them. But I hope, before I have done, to make it
evident, that this way of certainty, by the knowledge of our own ideas,
goes a little further than bare imagination: and I believe it will
appear that all the certainty of general truths a man has lies in
nothing else.

3. But what shall be the criterion of this agreement?

It is evident the mind knows not things immediately, but only by the
intervention of the ideas it has of them. Our knowledge, therefore, is
real only so far as there is a CONFORMITY between our ideas and the
reality of things. But what shall be here the criteri