De naturis rerum.
The Natures of Things, however, is not primarily a scientific or philosophical dissertation, as Alexander is careful to explain in the preface, but a vehicle for moral instruction. Natural phenomena are described, but following each comes some moral application or spiritual allegory thereof. The spots on the moon, for instance, are explained by some as due to mountains and to depressions which the sun’s light cannot reach, by others as due to the greater natural obscurity of portions of the moon. Neckam adds that they are for our instruction, showing how even the heavenly bodies were stained by the sin of our first parents, and reminding us that during this present life there will always be some blot upon holy church, but that when all the planets and stars shall stand as it were justified, our state too will become stable, and both the material moon and holy church will be spotless before the Lamb.[565] Neckam intends to admire God through His creatures and in so doing humbly to kiss as it were the feet of the Creator. Despite this religious tone and the moralizing, Wright regarded the work “as an interesting monument of the history of science in western Europe and especially in England during the latter half of the twelfth century,”[566] and as such we shall consider it. That it was written before 1200 is to be inferred from a quotation from it by a chronicler of John’s reign.[567] It seems to have been the best known of Neckam’s works. The brevity of The Natures of Things, which consists of but two books, if we omit the other three of its five books which consist of commentaries upon Genesis and Ecclesiastes, hardly allows us to call it an encyclopedia; but its title and arrangement by topics and chapters closely resemble the later works which are usually spoken of as medieval encyclopedias. Later in life Neckam wrote a poetical paraphrase of it with considerable changes, which is entitled De laudibus divinae sapientiae.
Neckam’s citations.
The citations of authorities in the De naturis rerum are of much interest. A number of references to the law books of Justinian show Neckam’s knowledge of the Roman law,[568] and, as we should expect after hearing of his commentary upon Ovid’s Metamorphoses, allusions to that work, the Fasti, and the Ars amandi are frequent. Claudian is once quoted for two solid pages and considerable use is made of other Latin poets such as Vergil, Lucan, Martial, and Juvenal. Neckam believed that the diligent investigator could find much that was useful in the inventions of the poets and that beneath their fables moral instruction sometimes lay hid.[569] Neckam quotes Plato, perhaps indirectly, and repeats in different words the fable of the crow and fox, as given in Apuleius.[570] The church fathers are of course utilized—Augustine, Jerome, Gregory, Basil, and a more recent theologian like Anselm, archbishop of Canterbury; and familiarity is shown with the early medieval standard authorities, such as Boethius, Cassiodorus, Bede, and Isidore. Of writers who may be regarded as dealing more particularly with natural science there are mentioned Pliny and Solinus on animals—but he seems to use Pliny very little and Solinus a great deal, Macer and Dioscorides on the properties and effects of herbs,[571] while works in the domain of astronomy or astrology are attributed to Julius (perhaps really Firmicus) and Augustus Caesar as well as to Ptolemy.[572]
His knowledge of Aristotle.
But what is most impressive is the frequent citation from Euclid and Aristotle, especially the latter. Not only the logical treatises are cited, but also the History of Animals[573] and the Liber Coeli et Mundi, while allusion is also made to Aristotle’s opinions concerning vision, motion, melancholy, waters, and various astronomical matters.[574] Such passages—as well as the fact that commentaries on Aristotle are ascribed to Neckam—suggest that Roger Bacon was mistaken in the much-quoted passage in which he states that the works of Aristotle on natural philosophy were first introduced to the medieval (Latin) learned world in Latin translations by Michael Scot about 1230. Neckam perhaps cites the History of Animals indirectly: at any rate he makes little use of it; but his numerous mentions of Aristotle’s views on nature make it evident that “the truth of Aristotelian” doctrine is already known in the twelfth century. And he already regards “the most acute Aristotle” as the pre-eminent authority among all philosophers. After stating that “all philosophers generally seem to teach” that the planets move in a contrary direction to the firmament like flies walking on a rushing wheel, Neckam adds a number of objections to this view, and adds, “It therefore was the opinion of Aristotle, the most acute, that the planets moved only with the firmament.” He then expresses his amazement that the other philosophers should have dared to oppose Aristotle, should have presumed to set their opinions against so great a philosopher. It is as if a peacock spread its spotted tail in rivalry with the starry sky, or as if owls and bats should vie with the eagle’s unblinking eye in staring at the mid-day sun.[575]
Use of recent authors.
That Neckam had some acquaintance with Arabic and Jewish writers is indicated by his citing Alfraganus and Isaac. Of Christian writers of the century before him Neckam quotes from Hildebert, and four times from Bernard Silvester. He cites the Pantegni or Tegni of Constantinus Africanus more than once.[576] He does not mention Adelard of Bath by name but in discussing experiments with vacuums repeats the experiment of the water jar. In another chapter he states that, if the earth were perforated, an enormous weight of lead would fall only to the center. Neckam’s chapter on “Why in the same earth plants grow of contrary effects” is similar to the third chapter of the Natural Questions of Adelard, and his chapter on “Why certain animals ruminate” is like Adelard’s seventh in the same work.[577]
Contemporary opinion of Neckam.
Roger Bacon, whose estimates of his contemporaries have sometimes been accepted at too high a value, wrote of Neckam some fifty years after Alexander’s death: “This Alexander wrote true and useful books on many subjects, but he cannot with justice be named as an authority.”[578] Bacon himself, however, seems on at least one occasion to have used Neckam as an authority without naming him.[579] On the other hand, another Englishman of note in science, Alfred of Sarchel or Sareshel, dedicated his book on The Movement of the Heart (De motu cordis) to Neckam.