“…You’re lying if you say you don’t know down in your heart that, in spite of anything I’ve done, I love you.”
Spade made a short abrupt bow. His eyes were becoming bloodshot, but there was no other change in his damp and yellowish fixedly smiling face. “Maybe I do,” he said. “What of it? I should trust you? You who arranged that nice little trick for – for my predecessor, Thursby? You who knocked off Miles, a man you had nothing against, in cold blood, just like swatting a fly, for the sake of double-crossing Thursby?”
Hammett, Dashiell. The Maltese Falcon (New York: Vintage Books, 1992), 212.
This quote quite succinctly sums up how Sam Spade operates at a basic level. Above all else, self-preservation is key for him. He is always looking out for himself alone, willing to drop anything and everyone to keep himself afloat. This section shows just how far he is willing to go, willing to surrender someone who he might truly love because he knows it will be safer for him in the long run. His moral code dictates that nothing is worth more than his own well-being.