What are the motifs in The Three Musketeers by Alexandre Dumas, pere?

Amorality is a recurring idea in the story. Despite their interest in true love, the characters are curiously amoral. If a woman is married, this is no obstacle to true love; they will happily have an affair with her if she's attractive enough. Although they defend each other to the death, they cheerfully kill any and all enemies and never give the dead another thought. And although they value honor and integrity, this does not extend to their enemies; d'Artagnan would defend Madame Bonacieux with his life, but he deceives Milady into making love with him in order to get revenge on her and lies to her maid Kitty, telling her he loves her to get information and help in his campaign against Milady.