The key to the expressionist style is the expression of emotion. The Impressionists provided the push that cast painting off from its long history of smooth representations of reality. Their loose brushwork, Gauguin's "primitive" style and Cezanne's experimentation with perspective opened the door for Expressionism. Dutchman Vincent van Gogh used energetic brushstrokes and vivid colors to impart emotional impact to his paintings. Norwegian Edvard Munch used flowing lines to depict anguish and love, while Austrians Gustav Klimt and Egon Schiele handled eroticism and death. Influences from outside the arts include Sigmund Freud's psychoanalysis and the calamity of the two World Wars. Experimentation with the expressionist style was perhaps most important in Germany. Though Hitler would attempt to squelch what he called "Degenerate Art," the style would spread throughout the world, and Expressionists like Wassily Kandinsky would pave the way for pure abstraction.