Great stress was laid by theologians, from St. Basil and St. Augustine to St. Thomas Aquinas and Bossuet, and from Luther to Wesley, on the radical distinction indicated in Genesis, God having created man "in his own image." What this statement meant was seen in the light of the later biblical statement that "Adam begat Seth in his own likeness, after his image."
In view of this and of well-known texts incorporated from older creation legends into the Hebrew sacred books it came to be widely held that, while man was directly moulded and fashioned separately by the Creator's hand, the animals generally were evoked in numbers from the earth and sea by the Creator's voice.
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.
But the feeling which we have already seen so strong in the early Church—that all study of Nature was futile in view of the approaching end of the world—indicated so clearly in the New Testament and voiced so powerfully by Lactantius and St. Augustine—held back this current of thought for many centuries. Still, the better tendency in humanity continued to assert itself. There was, indeed, an influence coming from the Hebrew Scriptures themselves which wrought powerfully to this end; for, in spite of all that Lactantius or St. Augustine might say as to the futility of any study of Nature, the grand utterances in the Psalms regarding the beauties and wonders of creation, in all the glow of the truest poetry, ennobled the study even among those whom logic drew away from it.
But, as a matter of course, in the early Church and throughout the Middle Ages all such studies were cast in a theologic mould. Without some purpose of biblical illustration or spiritual edification they were considered futile too much prying into the secrets of Nature was very generally held to be dangerous both to body and soul; only for showing forth God's glory and his purposes in the creation were such studies praiseworthy. The great work of Aristotle was under eclipse. The early Christian thinkers gave little attention to it, and that little was devoted to transforming it into something absolutely opposed to his whole spirit and method; in place of it they developed the Physiologus and the Bestiaries, mingling scriptural statements, legends of the saints, and fanciful inventions with pious intent and childlike simplicity. In place of research came authority—the authority of the Scriptures as interpreted by the Physio Cogus and the Bestiaries—and these remained the principal source of thought on animated Nature for over a thousand years.