This Roman pseudo-science could not, however, hold an important place in the thinking of the time: the fundamental conceptions that prevailed forbade it. The material world held a low place, as we have seen; on every side evidence can be found of an ascending scale of values from the material through the moral to the spiritual. Upon this idea is founded “the triple method of interpretation”[128] used in the Scriptures and elsewhere, and with it is connected the triple division of knowledge into natural science, ethics, and theology. There was not only an ascending scale of value for the different sorts of knowledge, but an ascending scale of validity. Spiritual truth and moral truth transcended the truth of material facts, whose stubbornness had been forgotten and had not yet been re-discovered. Yet, with all this depreciation of the material, it in some measure reasserted itself: as the literal meaning had to be grasped in the Scriptures before the higher meaning could be educed, so the material world had to be recognized before its higher meaning could be ascertained. This was the basis for science in the philosophy of the dark ages. [128] “Illud trimodum intelligentiae genus,” _Diff._, 2, 154. _Cf._ “Tripliciter autem scribitur, dum non solum historialiter vel mystice sed etiam moraliter quid in unum quodque gerere debeat edocetur.” _Contra Judaeos_, 2, 20. See also _De Ord. Creat._, 10, 4–7 and _Etym._, 6, 1, 11 (p. 186). In this way Isidore’s pseudo-science was brought into harmony with religion. Natural science was, indeed, concerned with the lowest and faintest form of reality, namely, the material world; but even material things had their spiritual implications, and because of this were worthy of an orderly survey. The _De Natura Rerum_, in which each term is explained first as it relates to the natural world and then as to its higher meaning, shows how science played the subordinate part just indicated. It is of great interest at this point to notice that Isidore’s successor, Rabanus Maurus, in his comprehensive encyclopedia _De Universo_, which follows Isidore’s _Etymologies_ closely, adds, however, the higher meanings which Isidore had left out in his work.[129] It is the importance of natural science from this point of view that Isidore has in mind in a passage in the _Sententiae_: “It does no harm to anyone if, because of simplicity, he has an inadequate idea of the elements, provided only he speaks the truth of God. For even though one may not be able to discuss the incorporeal and the corporeal natures, an upright life with faith makes him blessed.”[130]