Swans have always symbolized grace, dignity, and elegance. In Greek mythology, swans pull Apollo's chariot. Another Greek myth says that the soul of Apollo entered into a swan, and ever since, the soul of every good poet has passed into a swan. Because of its pure white color, the Greeks also associated the swan with purity and chastity. Interestingly, they also associated the swan with the gift of prophecy, and believed it could foretell its own death. In the Middle Ages, the pure and chaste aspects of the white swan, along with its beauty, made it a symbol of the Virgin Mary. Not surprisingly, the black swan became associated with Satan. An old story, dating back to Plato and Aristotle, says that swans sing beautifully when they are about to die. If you dream of a white swan swimming in the water, it's a sign that you're accomplishing your goals in a smooth, efficient, and seemingly effortless manner. If you dream of a black swan, you'll also achieve your goals, but it will take a great deal of time and effort.