This is the title of a play by
George Bernard Shaw. In the introduction, the author compares it to a play about
Don Juan which a friend once suggested he write. The protagonist however, at least as far as we see explicitely illustrated, is a philosphical but not a physical
libertine.
The play is about social hypocrisy ancient and modern (Mr. Shaws modern was some decades prior to ours). It begins with one man who avows his his determination to marry a woman - who seems almost ready to marry him. The protagonist seems both uninterested in and completely unsuited for marriage. If you are familiar with the twists and turns of George Bernard Shaw's plays you can guess which one she eventually chooses to marry, but first he desperately attempts to flee by a newfangled contraption called a motor car. Fate leads him to several odd encounters, including the ghost of Don Juan.
The motivations of the main characters are not quite what they seem to be at the beginning of the play.