Nineteenth-century Danish philosopher Søren Kierkegaard played a major role in the development of existentialist thought. Kierkegaard criticized the popular systematic method of rational philosophy advocated by German Georg Wilhelm Friedrich Hegel. He emphasized the absurdity inherent in human life and questioned how any systematic philosophy could apply to the ambiguous human condition. In Kierkegaard’s deliberately unsystematic works, he explained that each individual should attempt an intense examination of his or her own existence.