85-1. His success was attained but by friendly assistance.
We can say of such language as that of No. 85 only that it is idiomatic, thus justifying it as we justify the grammatical solecism “than whom.”
Mr. Wilson makes an exception to this mode of punctuation that is very perplexing; and it is probably because of this that few, if any, other writers refer to or deal with it.
We shall not attempt to discuss Mr. Wilson’s rule, but let us consider one of his examples:
86. It is not from wild beasts, but from untamed passions, that the greatest evils arise to human society.
We think the omission of a comma after “is,” thus suspending the negative group beginning with “not,” is justified, if at all, by the fact that such a sentence is usually read without a pause after the verb; in other words, the language thus readily groups itself, and shows the meaning and the force of the negative intermediate group.
Not a few good writers use a comma before “not” in sentences like No. 86.
If one or more words intervene between the verb and the negative particle, the parts of the sentence do not coalesce, and the comma is required.
87. He came not to teach, but to be taught.
87-1. He came here, not to teach, but to be taught.