For reference, here’s the M.L. Gill & P. Ryan translation of the Third Large or “Third Man” Argument (TMA) from the Parmenides. I include the argument that immediately follows, since it seems continuous with it, the next distinct objection being introduced with “And what about this?” at 132c6.
(I'll make it interlinear later, for ease of reference--Perseus seems to be down as I post this.)
[132a] “And what do you think about the following?"
“I suppose you think each form is one on the following ground: whenever some number of things seem to you to be large, perhaps there seems to be some one character, the same as you look at them all, and from that you conclude that the large is one.”
“That’s true,” he said.
“What about the large itself and the other large things? If you look at them all in the same way with the mind’s eye, again won’t some one thing appear large, by which all these appear large?” [Alternatively: “If you look at them all in the same way with the mind’s eye, won’t some one large again appear, by which all these appear large?”]
“It seems so.”
“So another form of largeness will make its appearance, which has emerged alongside largeness itself and the things that partake of it, and [132b] in turn another over all these, by which all of them will be large. Each of your forms will no longer be one, but unlimited in multitude.”
“But, Parmenides, maybe each of these forms is a thought [Alternatively: “But, Parmenides, maybe each of the forms is a thought of these things”], Socrates said, “and properly occurs only in minds. In this way each of them might be one and no longer face the difficulties mentioned just now.”
“What do you mean?” he asked. “Is each of the thoughts one, but a thought of nothing?”
“No, that’s impossible,” he said.
“Of something, rather?”
[132c] “Of something that is, or of something that is not?”
“Of something that is.”
“Isn’t if of some one thing, which that thought thinks is over all the instances, being some one character?”
"Then won’t this thing that is thought to be one, being always the same over all the instances, be a form?”
“That, too, appears necessary.”
“And what about this?” said Parmenides …