That's an interesting perspective. The falcon in the story is a figurine of course, but it does symbolize something to the characters. For Spade's secretary and her professor it's a romantic or historic mystery, for Sam Spade it's the elusive answer to all his questions. For the others, it's a symbolic quest, to actually posses this fabulous historic artifact. Of course, they want it for it's economic value, the fact that they would be rich, not for any historic value. And in a sense the falcon is simply luring them to their doom, some to death, some to prison, and Sam Spade back to his lonely life.
In Chapter 13 Gutman explains the history of the Maltese Falcon in great detail. Emperor Charles V gave the Knights of Rhodes Malta, Gozo, and Tripoli on condition that they pay him the annual tribute of one falcon "In the acknowledgment that Malta was still under Spain." The Knights decided to give the Emperor "a glorious golden falcon encrusted from head to foot with the finest jewels in their coffers." The Maltese Falcon originated as a symbol of loyalty, and loyalty is a principal theme throughout Hammett's novel. Wilmer Cook is loyal to Gutman. Floyd Thursby was loyal to Brigid O'Shaughnessy. In Chapter 19, Gutman tells Spade that he (Thursby) "was quite determinedly loyal to Miss O'Shaughnessy"). Captain Jacobi was also loyal to Brigid. Effie Perrine is exceedingly loyal to Sam Spade. Joel Cairo is loyal to General Kemidov, although the Russian, who knows the falcon is a fake, has sent him on a wild goose chase. (Kemidov himself is probably living in exile because he was loyal to the Czar.) Even Rhea Gutman is loyal to her father. (Loyalty was an important matter to Dashiell Hammett. In The Glass Key, one man takes a terrible beating out of loyalty to a friend.) Sam Spade is loyal to his partner in a sense, although he is disloyal in carrying on an affair with Archer's wife. Spade is loyal in his determination to avenge his partner's murder. ("When a man's partner is killed he's supposed to do something about it.") Brigid expects Spade to be loyal to her, but he deliberately tricks her into confessing that she killed Archer. Brigid herself is loyal to no one. Spade is self-reliant. He trusts nobody but himself. He is loyal to no one but himself. He has a low opinion of human nature, based on his experience as a police detective--and perhaps on his own assessment of himself.
In Native American symbolism, the falcon or hawk is extremely powerful. Hawks remind us that we must see things for what they really are, not for what we want them to be. Unfortunately, in today's world, society just doesn't have time. The hawk's eyes are made up of two lenses--one for seeing what is around him, and one for zooming in on his prey, which explains why they can dive with such accuracy from great heights. It is in this spirit that I suggest that the falcon, and the drive to obtain it, is a story about stripping away conventional wisdom to seek truth.