The Fourfold Root of the Principle of Sufficient Reason, tr. E. F. J. Payne (La Salle, Ill., 1974). Schopenhauer's first philosophical work, but in a revised edition incorporating much of his later thought. A useful and relatively clear introduction to some of the main themes of his philosophy, centered on the nature of causality.]
The World as Will and Idea, tr. R. B. Haldane and J. Kemp (3 vol., London, 1883). The original translation of Schopenhauer's compreshensive statement of his philosophy. But it contains over 1000 errors or omissions. The next entry is the preferred edition.]
The World as Will and Representation, tr. E. F. J. Payne (2 vol. Indian Hills, Col.,1958; rpt. New York, 1966). [Everything you really need to know about Schopenhauer's philosophy. All else simply develops themes found here. Volume one is an earlier edition; volume two consists of Schopenhauer's commentaries on the chapters in volume one. Volume two also has topical names for each chapter.]
On the Basis of Morality, tr. E. F. J. Payne (Indianapolis, 1965). [Comes in two parts. The first is a criticism of Kantian ethics, the second a statement of Schopenhauer's own views.]
Essay on the Freedom of the Will , tr. Konstantin Kolenda ( Indianapolis , 1960). [Originally it was half of a larger work, of which On the Basis of Morality was the first half.]
Parerga and Paralipomena: Short Philosophical Essays, tr. E. F. J. Payne (London, 1974). [The deluxe edition of Schopenhauer's essays. Contains all the most serious philosophical short works.]
Essays and Aphorisms, tr. Robert J. Hollingdale (Middlesex, 1970). [Readily available, containing mostly essays on life.]
Complete Essays, tr. T. Bailey Saunders (London, 1947).
The Pessimist's Handbook: a Collection of Popular Essays, tr. T. Bailey Saunders (Lincoln, Nebraska, 1964).
2. Secondary Sources.
Schopenhauer: Philosopher of Pessimism, F. C. Copleston (London, 1946; rpt. 1975). [A comprehensive survey of Schopenhauer's philosophy, with an attack on his pessimism from the standpoint of the Roman Catholic worldview.]
Schopenhauer, Patrick Gardiner (Middlesex, 1967). [A general survey of Schopenhauer's philosophy.]
Life of Schopenhauer, William Wallace (London, no date). [Written from an old-fashioned perspective.]
Arthur Schopenhauer: His Life and Philosophy, Helen Zimmern (London, 1876; rev. ed., 1932).