Marriage is not a mere chain upon love as the anarchists say; nor is it a mere crown upon love as the sentimentalists say. Marriage is a fact, an actual human relation like that of motherhood which has certain human habits and loyalties, except in a few monstrous cases where it is turned to torture by special insanity and sin. A marriage is neither an ecstasy nor a slavery; it is a commonwealth; it is a separate working and fighting thing like a nation. Kings and diplomatists talk of “forming alliances” when they make weddings; but indeed every wedding is primarily an alliance. The family is a fact even when it is not an agreeable fact, and a man is part of his wife even when he wishes he wasn’t. The twain are one flesh — yes, even when they are not one spirit. Man is duplex. Man is a quadruped.

-George Bernard Shaw (1909)