Love is moral even without legal marriage, but marriage is immoral without love. Ellen Key, "The Morality of Woman"
Love is the condition in which the happiness of another person is essential to your own. Robert A. Heinlein, "Stranger in a Strange Land"
Love talks and talks. Lust is brief and to the point. Mason Cooley, "City Aphorisms"
Love, and do what thou wilt: whether thou hold thy peace, through love hold thy peace; whether thou cry out, through love cry out; whether thou correct, through love correct; whether thou spare, through love do thou spare: let the root of love be within, of this root can nothing spring but what is good. St. Augustine of Hippo
Love, n. A temporary insanity curable by marriage or by removal of the patient from the influences under which he incurred the disorder. This disease is prevalent only among civilized races living under artificial conditions; barbarous nations breathing pure air and eating simple food enjoy immunity from its ravages. It is sometimes fatal, but more frequently to the physician than to the patient. Ambrose Bierce, "The Devil's Dictionary"
Love, the quest; marriage, the conquest; divorce, the inquest. Helen Rowland, "A Guide to Men"
Mad, adj. Affected with a high degree of intellectual independence. Ambrose Bierce, "The Devil's Dictionary"