A comma must not be placed before _that_ except when it is equivalent to _in order that_. "He says that he will be here."
A comma must not be placed before _and_ when it connects two words only. "Time and tide wait for no man." "A rich and prosperous people." "Plain and honest truth wants no artificial covering."
A comma is sometimes necessary to prevent ambiguity. "He who pursues pleasure only defeats the object of his creation." Without a comma before or after _only_, the meaning of this sentence is doubtful.
The following sentences present some miscellaneous examples of the use of the comma by writers on punctuation: "Industry, as well as genius, is essential to the production of great works." "Prosperity is secured to a state, not by the acquisition of territory or riches, but by the encouragement of industry." "Your manners are affable, and, for the most part, pleasing."[27]
"However fairly a bad man may appear to act, we distrust him." "Why, this is rank injustice." "Well, follow the dictates of your inclination." "The comma may be omitted in the case of _too_, _also_, _therefore_, and _perhaps_, when introduced so as not to interfere with the harmonious flow of the period; and, particularly, when the sentence is short."[28] "Robert Horton, M. D., F. R. S." "To those who labor, sleep is doubly pleasant"; "Sleep is doubly pleasant to those who labor." "Those who persevere, succeed." "To be overlooked, slighted, and neglected; to be misunderstood, misrepresented, and slandered; to be trampled under foot by the envious, the ignorant, and the vile; to be crushed by foes, and to be distrusted and betrayed even by friends--such is too often the fate of genius." "She is tall, though not so handsome as her sister." "Verily, verily, I say unto you." "Whatever is, is right." "What is foreordained to be, will be." "The Emperor Augustus was a patron of the fine arts." "Augustus, the Emperor, was a patron of the fine arts." "United, we stand; divided, we fall." "God said, Let there be light." "July 21, 1881." "President Garfield was shot, Saturday morning, July 2, 1881; he died, Monday night, Sept. 19, 1881." "I am, sir, very respectfully, your obedient servant, John Jones." "New York, August, 1881." "Room 20, Equitable Building, Broadway, New York."