Mathematicians, philosophers and physicists at the beginning of the 20th century were recognising that many absolute truths were convenient caricatures of a universe that might be far stranger, far further from common sense than anyone thought. Western painting had its own scientific assumptions, established in the Renaissance. Picasso and Braque unmasked these as conventions. The concepts of absolute gravity and time that gave way to relative ones in the early 20th century had been established by Newton in the 1600s. The doctrine of single-point perspective, whose inadequacies Braque and Picasso exposed, had been asserted by Leon Battista Alberti and Filippo Brunelleschi two centuries before.Pretentious twaddle! Art draws on perfectible techniques; science limitlessly accrues knowledge.
The perspective system invented in Florence in the 15th century was a shorthand for the way things looked, a brilliantly usable fiction of the appearance of the world. Our sense impressions are complicated, chaotic data that the brain has to make sense of. Seeing in pictures appears to be necessary in our lives. Alberti and Brunelleschi showed how those pictures can be made consistent and logical by fixing a distant point towards which objects recede - what's further away looks smaller than what's near. [Picasso and Braque] did not make their intellectual revolution against this centuries-old system in a cool, considered mood, but with turbulence and fury. There was a violence in their assault on perspective.
Picasso's first essay in the new painting, Les Demoiselles d'Avignon (1907), associates the death of the picture with sexual aggression and "primitive" release. It is an overturning of civilised lies, one of which is the neat illusion of perspective. Braque put his anger into words. "The whole Renaissance tradition is antipathetic to me," he said. "The hard-and-fast rules of perspective, which it succeeded in imposing on art, were a ghastly mistake..."
The truth is that in art -- as in "serious" music -- the best work that could be done had been done by about 1900. That left Picasso, Braque, and their ilk -- like Schoenberg, Berg, and their ilk -- with two options: Create new works using the tools that had been perfected by the masters who came before them, or disown the tools in a fit of adolescent rebellion. The artists and "serious" composers of the 20th century, in the main, took the second option.