Abstract Expressionism, also known as The New York School and sometimes referred to as Action School painting, is the "language of emotions" as Mark Rothko famously said. There was a new emphasis on paint itself as an expressive medium. For this generation of Post WWII painters, the canvas is acted upon, like a skirmish, as the critic Harold Rosenberg might have envisioned. The tension within the painting makes the work successful. They felt that painting should not be easy, they were responding to a crisis, often an existential crisis. They sought to break free of the past and create something new and heroic.