In what way?
Because the others are other than the one inasmuch as they have parts; for if they had no parts they would be simply one.
Right.
And parts, as we affirm, have relation to a whole?
So we say.
And a whole must necessarily be one made up of many; and the parts will be parts of the one, for each of the parts is not a part of many, but of a whole.
How do you mean?
If anything were a part of many, being itself one of them, it will surely be a part of itself, which is impossible, and it will be a part of each one of the other parts, if of all; for if not a part of some one, it will be a part of all the others but this one, and thus will not be a part of each one; and if not a part of each, one it will not be a part of any one of the many; and not being a part of any one, it cannot be a part or anything else of all those things of none of which it is anything.
Clearly not.
Then the part is not a part of the many, nor of all, but is of a certain single form, which we call a whole, being one perfect unity framed out of all—of this the part will be a part.