"For as his own bright image he surveyed,

He fell in love with the fantastic shade;

And over the fair resemblance hung unmoved,

Nor knew, fond youth! It was himself he loved."      

--Ovid, Metamorphoses.                                               

In Greek mythology, Narcissus was a handsome youth who had un-resistible attraction to many who saw him. One was the nymph Echo, who could only repeat the last thing that anyone said. When Echo encountered Narcissus in the woods and revealed her love to him, Narcissus cruelly rejected her. She wasted away to nothing but her voice. Though Narcissus disdained the affection of others, he became the victim of his own attractiveness. Later, Narcissus came to a still pool. When he caught sight of his own reflection, he fell to his knee, gazing at himself in fascination. For days he was tantalized by his image, unable to drink or eat. When he finally died, the gods turned him into a narcissus, which stands with its head bent as if still gazing at its own reflection. 

Caravaggio captured the moment when Narcissus lost himself in his own beauty. Surrounded by darkness, the figure and his reflection form a circle, which, on the one hand, rejects external world, while on the other hand, completes the unity of self and the idea of self. According to the story, Narcissus didn't know what he looked like beforehand, because otherwise he would be gazing at a mirror or the back of a silver spoon. Therefore, if one agrees that Narcissus represents the idea of ultimate beauty, one must also acknowledge the power of witnessing such a beauty. Thus on my conjecture, although Narcissus's excessive love of himself is almost tangible in this painting, still, Caravaggio conveyed a message rather upholds the importance of recognizing the beauty within oneself, instead of criticizing narcissism.