Paintings needed to serve as useful and accurate historical documents, and therefore had to appear realistic. Because painting supplies were rare, they could not be wasted on unrealistic art.
Bernini's David invokes many emotions and the sculpture itself is extremely emotional and dramatic. Michelangelo's David while slightly emotional displays more intellectual aspects than emotional aspects.
For most of the history of art, the SUBJECT is recognisable or at least reflects some sort of visual experience. Artists work with types of subjects that are reffered to as GENRES which among other things, include genre subjects which are images and themes which are experienced in ordinary life.
