A question now arose naturally as to the DISTINCTIONS OF SPECIES among animals. The vast majority of theologians agreed in representing all animals as created "in the beginning," and named by Adam, preserved in the ark, and continued ever afterward under exactly the same species. This belief ripened into a dogma. Like so many other dogmas in the Church, Catholic and Protestant, its real origins are to be found rather in pagan philosophy than in the Christian Scriptures; it came far more from Plato and Aristotle than from Moses and St. Paul. But this was not considered: more and more it became necessary to believe that each and every difference of species was impressed by the Creator "in the beginning," and that no change had taken place or could have taken place since. Some difficulties arose here and there as zoology progressed and revealed ever-increasing numbers of species; but through the Middle Ages, and indeed long after the Reformation, these difficulties were easily surmounted by making the ark of Noah larger and larger, and especially by holding that there had been a human error in regard to its measurement.(13) (13) For St. Augustine, see De Genesis and De Trinitate, passim; for Bede, see Hexaemeron, lib. i, in Migne, tome xci, pp. 21, 36-38, 42; and De Sex Dierum Criatione, in Migne, tome xciii, p. 215; for Peter Lombard on "noxious animals," see his Sententiae, lib. ii, dist. xv, 3, Migne, tome cxcii, p. 682; for Wesley, Clarke, and Watson, see quotations from them and notes thereto in my chapter on Geology; for St. Augustine on "superfluous animals," see the De Genesi, lib. i, cap. xvi, 26; on Luther's view of flies, see the Table Talk and his famous utterance, "Odio muscas quia sunt imagines diaboli et hoereticorum"; for the agency of Aristotle and Plato in fastening the belief in the fixity of species into Christian theology, see Sachs, Geschichte der Botanik, Munchen, 1875, p. 107 and note, also p. 113. But naturally there was developed among both ecclesiastics and laymen a human desire to go beyond these special points in the history of animated beings--a desire to know what the creation really IS. Current legends, stories, and travellers' observations, poor as they were, tended powerfully to stimulate curiosity in this field. Three centuries before the Christian era Aristotle had made the first really great attempt to satisfy this curiosity, and had begun a development of studies in natural history which remains one of the leading achievements in the story of our race.