Homo unius libri
Homo unius libri ("(a) man of one book") is a Latin phrase attributed to Thomas Aquinas in a literary tradition going back to at least the 17th century, bishop Jeremy Taylor (1613–1667) being the earliest known writer in English to have done so. Saint Thomas Aquinas is reputed to have employed the phrase ""hominem unius libri timeo"" (meaning "I fear the man of a single book"). There are other attributions, and variants of the phrase. Variants include "cave" ("beware") for "timeo", and "virum" ("man") or "lectorem" ("reader") for "hominem". "The Concise Dictionary of Foreign Quotations" (London 1998 ), attributes the quote to Augustine of Hippo. It has also been attributed to Pliny the Younger, Seneca or Quintilian, but the existence of the phrase cannot be substantiated as predating the early modern period. The phrase was in origin a dismissal of eclecticism, i.e. the "fear" is of the formidable intellectual opponent who has dedicated himself to and become a master in a single chosen discipline. In this first sense, the phrase was used by Methodist founder John Wesley, referring to himself, with "one book" taken to mean the Bible. However, the phrase today most often refers to the  interpretation of expressing "fear" of the opinions of the illiterate man who has "only read a single book". Interpretations. Mastery of a single topic. The literary critic Clarence Brown described the phrase in his introduction to a novel by Yuri Olesha: The poet Robert Southey recalled the tradition in which the quotation became embedded: By way of comparison, Southey quotes Lope de Vega's "Isidro de Madrid" expressing a similar sentiment, The writer and naturalist Charles Kingsley, following the tradition laid down by Gilbert White in "The Natural History and Antiquities of Selborne" (1789), also invoked the proverb in favour  of knowing completely one small area. "A lesson is never learnt till it is learnt over many times, and a spot is best understood by staying in it and mastering it. In natural history the old scholar's saw "Cave hominem unius libri" may be paraphrased by, 'He is a thoroughly good naturalist who knows one parish thoroughly.'" John Wesley invoked the phrase in this sense and declared himself to be a "homo unius libri", the "one book" being the Bible. Like Methodists in the strict Wesleyan tradition of depending upon the One Book, many seventeenth-century and modern radical  Protestants have prided themselves on being "homines unius libri". The poet William Collins in his deranged condition, met by chance his old friend Samuel Johnson, who found Collins carrying a New Testament. "I have but one book," said Collins, "but it is the best". Narrow learning. Edward Everett applied the remark "not only to the man of one book, but also to the man of one idea, in whom the sense of proportion is lacking, and who sees only that for which he looks". Joseph Needham, in the general conclusions to his "Science and Civilisation in China" series, observed of  the saying, "It could mean that this man has only read one book, has only written one book, does not possess more than one book, or puts his faith in one book only. The fear that is felt may be on behalf of the man himself. Having read so little he is quite at the mercy of his one book!" Limited success as an author. In Samuel Butler's "The Way of All Flesh" (1903), a publisher uses the phrase to describe the novel's protagonist. Butler also records that his own publisher, "Trübner", applied the phrase to him to  express doubts in his literary prospect, the "one book" of Butler's in this case being "Erewhon".