_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_. [Sidenote: Neckam’s citations.]