Although Edgeworth was strong in mathematics, he was weak at prose, and his publications failed to reach a popular audience. He had hoped to use mathematics to illuminate ethical questions, but his first work, New and Old Methods of Ethics (1877), depended so heavily on mathematical techniques—especially the calculus of variations—that the book may have deterred otherwise interested readers. His most famous work, Mathematical Psychics (1881), presented his new ideas on the generalized utility function, the indifference curve, and the contract curve, all of which have become standard devices of economic theory.