A bachelor's life is no life for a single man.
It is a truth universally acknowledged, that a single man in possession of a good fortune, must be in want of a wife.
I am an unmarried man, as opposed to a single man. A bachelor, according to the dictionary, is a man who has never been married. An unmarried man is not married at the moment. Many of these terms have fallen into disuse.
The notion of the single man began in the 1950's. The idea of the bachelor as a separate life was new and obscure.
If a wise man behaves prudently, how can he be overcome by his enemies? Even a single man, by right action, can overcome a host of foes.