Samuel Jay Keyser: "Modernism, considered to be the greatest transformation of art forms in the West, is the name given to the shift in the sister arts that occurred around the turn of the 20th century. Poetry ceased to be metrical and to rhyme, music ceased to be tonal and painting ceased to be representational. Typically, these changes are explained in cultural terms. The artist, Paul Delaroche is reputed to have declared in 1838 when he saw the first daguerreotype, “Painting is dead.” Meter and rhyme were viewed by Ezra Pound as procrustean beds curtailing the emotional content of poetry. And Richard Taruskin, author of the monumental Oxford History of Western Music, saw the apocalyptic presentiments occasioned by the calendar turning from 1899 to 1900 as ushering atonality.
From my perspective, the difficulty with these explanations is that they are sui generis. They do not generalize. It is hard to see how the camera induced free verse or how apocalyptic presentiments ushered in cubism. Of course, it may be that the three developments are, indeed, independent of one another. But there are two things that point toward a relationship. The first is that in all three cases something ceased to be. The second is that in all three cases unlike the art forms that were abandoned, the art forms that moved in to fill the vacuum were inherently inaccessible and required some effort, in many cases, considerable effort, to be appreciated.
In view of this, I would like to place another explanation for Modernism on the table. I would like to suggest that Modernism resulted from a cognitive shift away from bodies of knowledge (I call them rules) that catered to the natural predilections of the brain to new bodies of knowledge that didn’t. I suggest that this shift is not new but occurred once before in western intellectual history; namely, when Isaac Newton’s view of the relationship between physical objects displaced the mechanistic view at the turn of the 17th century."