"And are you undecided about certain other things, which you might think rather ridiculous, such as hair, mud, dirt, or anything else particularly vile and worthless? Would you say that there is an idea of each of these distinct and different from the things with which we have to do, or not?"
"By no means," said Socrates. "No, I think these things are such as they appear to us, and it would be quite absurd to believe that there is an idea of them; and yet I am sometimes disturbed by the thought that perhaps what is true of one thing is true of all. ... "
Parmenides 130 c - d