SCHOPENHAUER'S magnificent work, The World as Will and Idea (Die Welt als Wille und Vorstellung), published in 1819, is not only a masterly exposition of philosophy, but a comprehensive record of Schopenhauer's own views on mankind. The keynote of his philosophy is that the sole essential reality in the universe is the will, and that all visible and tangible phenomena are merely subjective representations of that 'will which is the only thing-in-itself' that actually exists. The defect of his system is its tendency to a sombre pessimism. An enlarged edition appeared in 1844. The chief of Schopenhauer's other works are On the Will in Nature (1836), The Main Problems of Ethics (1841), and Parerga and Paralipomena (1851). 'THE world is my idea' is a truth valid for every living creature, though only man can consciously contemplate it. In doing so he attains philosophical wisdom. No truth is more absolutely certain than that all that exists for knowledge, and, therefore, this whole world, is only object in relation to subject, perception of a perceiver--in a word, idea. The world is idea.