_When a sentence consists of three or more clauses, united by a conjunction, none of which are susceptible of division, a semicolon should be put between those_ _which are least connected in sense, and a comma only between the others._
To illustrate this rule, the following sentence is given in Mr. Wilson’s book (the italics are ours):
22. The woods may disappear, _but_ the spirit of them never will now; _for_ it has been felt by a poet, _and_ we can feel for ever[5] what he felt.
Does the punctuation indicate the real sense relations in this sentence? We think not. The semicolon before “for” divides the sentence into two parts; but what follows the semicolon is clearly not in the _for_ relation with all that precedes it, as it should be if the sentence is divided into two parts at this point. The sense relation expressed by “for” is unmistakably between all that follows it and what precedes it back to “but.”
The real division of the sentence into two parts is made at “but,” as shown in the following:
22-1. The woods may disappear, but the spirit of them never will now.
Expanding the above, to emphasize the relations, but still maintaining the sense of No. 22, we get the following:
22-2. The woods may disappear, for they are material and will decay; but the spirit of them never will now, for it has been felt by a poet and we can feel forever what he felt.
In No. 22-2 we added a commonplace modifier to the first statement in the sentence, in order to exhibit more clearly the similar relation between two like groups in the second part of the sentence, which take a semicolon in the quoted sentence (No. 22).
Punctuated so as to show the real sense relations, the sentence reads as follows:
22-3. The woods may disappear: but the spirit of them never will now; for it has been felt by a poet, and we can feel forever what he felt.
A thorough comprehension of the groupings in these sentences, which is based upon sense relations, will illuminate the punctuation already discussed. It will also explain some apparent, if not real, inconsistencies that are inevitable in dealing with marks to express indefinite degrees of relation.
Sentence 1 is composed of two clauses connected by a conjunction, as is also Sentence 22-1. The liability to error in grouping Sentence 1 may be sufficient to require a semicolon; but the grouping in Sentence 22-1 is so unmistakable that a comma is sufficient to give notice of a change in the direction of the thought. In Sentence 21 the semicolon gives notice of a grouping which does not follow. In Sentence 22 the grouping by punctuation does not follow the meaning of the language, and is therefore wrong.