[25] A Jesuit of the sixteenth century thus shortly and clearly distinguishes the positive from the scholastic, and both from natural or metaphysical theology. At nos theologiam scholasticam dicimus quæ certiori methodo et rationibus imprimis ex divina scriptura ac traditionibus seu decretis patrum in conciliis definitis veritatem eruit, ac discutiendo comprobat. Quod cum in scholis præcipue argumentando comparetur, id nomen sortita est. Quamobrem differt a positiva theologia, non re sed modo, quemadmodum item alia ratione non est eadem cum naturali theologia, quo nomine philosophi metaphysicen nominarunt. Positiva igitur non ita res disputandas proponit, sed pæne sententiam ratam et firmam ponit, præcipue in pietatem incumbens. Versatur autem et ipsa in explicatione Scripturæ sacræ, traditionum, conciliorum et sanctorum patrum. Naturalis porro theologia Dei naturam per naturæ argumenta et rationes inquirit, cum supernaturalis, quam scholasticam dicimus, Dei ejusdem naturam, vim, proprietates, cæterasque res divinas per ea principia vestigat, quæ sunt hominibus revelata divinitas. Possevin, Bibliotheca Selecta, l. 3. c. i. Both positive and scholastic theology were much indebted to Peter Lombard, whose Liber Sententiarum is a digest of propositions extracted from the fathers, with no attempt to reconcile them. It was therefore a prodigious magazine of arms for disputation. [26] The first of these, according to Tennemann, begins the list of schoolmen with Hales; the two latter agree in conferring that honour on Albertus Magnus. Brucker inclines to Roscelin, and has been followed by others. It may be added, that Tennemann divides the scholastic philosophy into four periods, which Roscelin, Hales, Ockham, and the sixteenth century terminate; and Buhle into three, ending with Roscelin, Albertus Magnus, and the sixteenth century. It is evident, however, that, by beginning the scholastic series with Roscelin, we exclude Lanfranc and even Anselm; the latter of whom was certainly a deep metaphysician; since to him we owe the subtle argument for the existence of a Deity, which Des Cartes afterwards revived. Buhle, 679. This argument was answered at the time by one Gaunelo; so that metaphysical reasonings were not unknown in the eleventh century. Tennemann, 344.