Good art is done within a tradition according to accepted standards that can be excellent.
When a High Renaissance painter painted he had to observe period conventions, like perspective, or he would not have gotten lucrative commissions, such as for the Church.
The better the painter realized those conventions, the more he achieved the standard of the day, what people expected, and thus defined his work according to those expectations.
What is true of Renaissance painters is true of all genres: Mary Cassatt (a great artist) followed the conventions of Impressionism when she had her figures bathed in light, a soft one. Following this convention allowed her to explore it but also set limits on her art.
Good art achieves the conventions of its time and genre, but does not venture beyond that: those who do it, don’t think outside the box, cave wall, or canvass: this is their limitation.
Great art, while honoring conventions, goes beyond them, that is, beyond people’s expectations of what happens when you make art or observe it: it welcomes challenges.
Oscar Wilde once observed that before W.M. Turner people had not seen a sunset.
Artists before Turner had painted scads of sunsets but Turner conveyed ‘light’ that artists had seen but had not been able to render: great art does what has not been done before.
Great art illuminates profound truths: the Sistine Chapel offers us insight into the Bible.
So great art is like great tarts: only master chefs bake them and you never forget the taste
