The book, first published in 1883, tells the history of vegetarianism since the writings of the first Pythagorean philosophers of the Ancient World until the author’s time. Among the authors mentioned in the book are: Ovid, Plutarch, Porphyry, Luigi Cornaro, Michel de Montaigne, John Ray, Voltaire, Alexander Pope, Percy Shelley, Alphonse de Lamartine, Joseph Ritson, and Gustav Struve. Not all authors mentioned in the book were vegetarians, but they all had critical views of meat-eating. It was of some importance at the time. As Jon Gregerson wrote in Vegetarianism: A History, “Not unimportant in the momentum gathered by the Vegetarian Movement in late Victorian England was a book by one Howard Williams entitled The Ethics of Diet, which was published in 1890”. It was read by Indian spiritual leaderMohandas Gandhi, Russian writerLeo Tolstoy, English social reformerHenry Stephens Salt, and PortuguesephilosopherJaime de Magalhães Lima. Gandhi, who met Williams in Ventnor, wrote in his autobiography: "My faith in vegetarianism grew on me from day to day. Salt's book Plea for Vegetarianism whetted my appetite for dietetic studies. I went in for all books available on vegetarianism and read them. One of these, Howard Williams' The Ethics of Diet, was a 'biographical history of the literature of humane dietetics from the earliest period to the present day'". Tolstoy considered it an “excellent book”, and in 1892 he wrote the preface to the Russian translation. According to Tolstoy, “The precise reason why abstinence from animal food will be the first act of fasting and of a moral life is admirably explained in the book, The Ethics of Diet; and not by one man only, but by all mankind in the persons of its best representatives during all the conscious life of humanity." Henry Stephens Salt commented that “Of all recent books on the subject of animals’ rights this is by far the most scholarly and exhaustive”. Jaime de Magalhães Lima,, used Williams book as a reference to write his 1912 conference O Vegetarismo e a Moralidade das raças . In 1896 a new edition appeared with additional material. The book however became a rarity, only available in certain libraries. In 2003, the University of Illinois Press edited a new edition with an additional introduction by eco-feminism author Carol J. Adams.