Three Dialogues Between Hylas and Philonous

PHILONOUS: I do not pretend to be a setter-up of new notions. My endeavours tend only to unite and place in a clearer light that truth, which was before shared between the vulgar and the philosophers: the former being of opinion, that those things they immediately perceive are the real things; and the latter, that the things immediately perceived, are ideas which exist only in the mind. Which two notions put together, do in effect constitute the substance of what I advance.
HYLAS: I have been a long time distrusting my senses; I thought I saw things by a dim light, and through false glasses. Now the glasses are removed, and a new light breaks in upon my understanding. I am clearly convinced that I see things in their native forms; and am no longer in pain about their unknown natures or absolute existence. This is the state I find myself in at present: though indeed the course that brought me to it, I do not yet thoroughly comprehend. You set out upon the same principles that Academics, Cartesians, and the like sects, usually do; and for a long time it looked as if you were advancing their philosophical scepticism; but in the end your conclusions are directly opposite to theirs.
PHILONOUS: You see, Hylas, the water of yonder fountain, how it is forced upwards, in a round column, to a certain height; at which it breaks and falls back into the basin from whence it rose: its ascent as well as descent, proceeding from the same uniform law or principle of gravitation. Just so, the same principles which at first view lead to scepticism, pursued to a certain point, bring men back to common sense.