Tyc. Out with it, then, as you know.
Si. An art, as I once heard a wise man say, is a body of perceptions regularly employed for some useful purpose in human life.
Tyc. And he was quite right.
Si. So, if sponging has all these marks, it must be an art?
Tyc. If, yes.
Si. Well, now we will bring to bear on sponging each of these essential elements of Art, and see whether its character rings true, or returns a cracked note like bad pottery when it is tapped. It has got to be, like all art, a body of perceptions. Well, we find at once that our artist has to distinguish critically the man who will entertain him satisfactorily and not give him reason to wish that he had sponged elsewhere. Now, in as much as assaying—which is no more than the power of distinguishing between false and true coin—is a recognized profession, you will hardly refuse the same status to that which distinguishes between false and true men; the genuineness of men is more obscure than that of coins; this indeed is the gist of the wise Euripides’s complaint:
But among men how tell the base apart?
Virtue and vice stamp not the outward flesh.
So much the greater the sponger’s art, which beats prophecy in the certainty of its conclusions upon problems so difficult.
Next, there is the faculty of so directing your words and actions as to effect intimacy and convince your patron of your devotion: is that consistent with weak understanding or perception?
Tyc. Certainly not.