How does David (Bernini) elucidate its Influences?
The biblical David was a popular subject among Renaissance artists and had been treated by sculptors such as Donatello (c.1440s), Verrocchio (1473-1475) and Michelangelo (1501-1504). Bernini's David, though engaging with these works, differed from them in some significant ways.
For one thing, the sculpture is no longer self-contained, but interacts with the space around it. Not since the sculptures of the Hellenistic period, such as the Winged Victory of Samothrace, had sculptures been involved in their surroundings like those of Bernini. A likely source for Bernini's figure was the Hellenistic Borghese Gladiator. The motion of the  gladiator preparing to attack is similar to how David is swinging his sling. Another difference lies in the moment that Bernini has chosen to depict. Michelangelo's David differs from those of Donatello and Verrocchio in that it shows David preparing for the battle, rather than victorious afterwards. Bernini, on the other hand, chose to portray David in the act of throwing the stone. This represented a novelty; throwing figures were extremely rare in post-Antiquity sculptures. The motion motif did exist in painting, however, and one example was Annibale Carracci's fresco of the Cyclops Polyphemus throwing a stone. Bernini is likely to have known Carracci's Polyphemus; not only was it to be found in the Galleria Farnese in Rome, but Carracci was the painter Bernini ranked as fourth among the greatest ever.Bernini may also have been familiar with the writings of Leonardo da Vinci on the subject. Da Vinci, in his Treatise on Painting, deals with exactly the question of how to portray a throwing figure. It is possible that Bernini applies this theory to his David:If you represent him beginning the motion, then the inner side of the outstretched foot will be in line with the chest, and will bring the opposite shoulder over the foot on which his weight rests. That is: the right foot will be under his weight, and the left shoulder will be above the tip of the right foot.
Another potential candidate as inspiration for Bernini's David is the celebrated 5th century BC Discobolus by Myron. However, the problem with this theory is that the Discobolus was in the early 17th century only known from literary sources; the torsos of copies that had survived were not correctly identified until 1781. Both Quintilian and Lucian wrote of the statue, but the descriptions were of a figure stretching or flexing, rather than being in the act of throwing.
Borghese Gladiator Annibale Carracci Winged Victory of Samothrace Lucian Hellenistic Cyclops Michelangelo Galleria Farnese Renaissance Rome Discobolus David fresco Treatise on Painting Myron Polyphemus Donatello Leonardo da Vinci sling Quintilian Verrocchio