EXCEPTION III.—ALTERNATIVE OF WORDS.
When there is merely an alternative of names, or an explanatory change of terms, the comma is usually inserted; as, "We saw a large opening, or inlet."—W. Allen. "Have we not power to lead about a sister, a wife, as well as other apostles?"—Cor., ix, 5.
EXCEPTION IV.—CONJUNCTION UNDERSTOOD.
When the conjunction is understood, the comma is inserted; and, if two separated words or terms refer alike to a third term, the second requires a second comma: as, "Reason, virtue, answer one great aim."—L. Murray, Gram., p. 269.
"To him the church, the realm, their pow'rs consign."—Johnson.
"She thought the isle that gave her birth.
The sweetest, wildest land on earth."—Hogg.
RULE V.—WORDS IN PAIRS.
When successive words are joined in pairs by conjunctions, they should be separated in pairs by the comma; as, "Interest and ambition, honour and shame, friendship and enmity, gratitude and revenge, are the prime movers in public transactions."—W. Allen. "But, whether ingenious or dull, learned or ignorant, clownish or polite, every innocent man, without exception, has as good a right to liberty as to life."—Beattie's Moral Science, p. 313.
"Then say how hope and fear, desire and hate,
O'erspread with snares the crowded maze of fate."—Dr. Johnson.