HYL.  Believe me, Philonous, you can only distinguish between your own ideas.  That yellowness, that weight, and other sensible qualities, think you they are really in the gold?  They are only relative to the senses, and have no absolute existence in nature.  And in pretending to distinguish the species of real things, by the appearances in your mind, you may perhaps act as wisely as he that should conclude two men were of a different species, because their clothes were not of the same colour.

Phil.  It seems, then, we are altogether put off with the appearances of things, and those false ones too.  The very meat I eat, and the cloth I wear, have nothing in them like what I see and feel.

HYL.  Even so.

Phil.  But is it not strange the whole world should be thus imposed on, and so foolish as to believe their senses?  And yet I know not how it is, but men eat, and drink, and sleep, and perform all the offices of life, as comfortably and conveniently as if they really knew the things they are conversant about.

HYL.  They do so:  but you know ordinary practice does not require a nicety of speculative knowledge.  Hence the vulgar retain their mistakes, and for all that make a shift to bustle through the affairs of life.  But philosophers know better things.

Phil.  You mean, they know that they know nothing.

HYL.  That is the very top and perfection of human knowledge.

Phil.  But are you all this while in earnest, Hylas; and are you seriously persuaded that you know nothing real in the world?  Suppose you are going to write, would you not call for pen, ink, and paper, like another man; and do you not know what it is you call for?

HYL.  How often must I tell you, that I know not the real nature of any one thing in the universe?  I may indeed upon occasion make use of pen, ink, and paper.  But what any one of them is in its own true nature, I declare positively I know not.  And the same is true with regard to every, other corporeal thing.  And, what is more, we are not only ignorant of the true and real nature of things, but even of their existence.  It cannot be denied that we perceive such certain appearances or ideas; but it cannot be concluded from thence that bodies really exist.  Nay, now I think on it, I must, agreeably to my former concessions, farther declare that it is impossible any real corporeal thing should exist in nature.

Phil.  You amaze me.  Was ever anything more wild and extravagant than the notions you now maintain:  and is it not evident you are led into all these extravagances by the belief of material substance?  This makes you dream of those unknown natures in everything.  It is this occasions your distinguishing between the reality and sensible appearances of things.  It is to this you are indebted for being ignorant of what everybody else