The qualities cultivated by dialectic, and the impartial rational temper, here displayed, reappear in the works of Abaelard devoted to sacred doctrine. Enough has been said of the method and somewhat captious qualities of the _Sic et non_.[475] Unquestionably its manner of presenting the contradictory opinions of the Fathers, without any attempt to reconcile them, tended to bring into view the difficulties inhering in the formulation of Christian belief. And indeed the book made prominent all the diabolic insoluble problems of the Faith, or rather of life itself and any view of God and man: Predestination, for example; whether God causes evil; whether He is omnipotent; whether He is free. The Lombard’s _Sentences_ and Thomas’s _Summa_ considered all these questions; but they strove to solve them; and Thomas did solve every one, leaving no loose ends to his theology. More potently than Abaelard did the Angelic Doctor employ dialectic in his finished scheme. With him, this propaedeutic discipline, this tool of truth, perfectly performs its task of construction. So also Abaelard intended to work with it; but his somewhat unconsidered use of the tool did not meet the approval of his contemporaries. Accordingly, in his more constructive theological treatises his impulse to know and state appears finally actualized in the systematic formulation of convictions upon topics of ultimate interest, to wit, theology, the contents of the Christian Faith, the full relationship of God and man. Did he sever theology from philosophy? Nay, rather, with him theology was ultimate philosophy. Several times Abaelard rewrote what was substantially the same general work upon Theology. In one of its earliest forms it was burnt by the Council of Soissons in 1121.[476] In another form it exists under the title _Theologia Christiana_;[477] and the first part of its apparently final revision is now improperly entitled, _Introductio ad theologiam_.[478] The first Book of the _Theologia Christiana_ is an exposition of the Trinity, not clinched in syllogisms, but consisting mainly of an orderly presentation of the patristic authorities supporting the author’s view of the matter. The testimonies of profane writers are also given. Liber II. opens by saying that in the former part of the work “we have collected the _testimonia_ of prophets and philosophers, in support of the faith of the Holy Trinity.” Hereupon, by the same method of adducing authorities, Abaelard proceeds to refute those who had blamed him for citing the pagan philosophers. He marshals his supporting excerpts from the Fathers, and remarks: “That nothing is more needful for the defence of our faith than that as against the importunities of all the infidels we should have witness from themselves wherewith to refute them.” Then he points to the moral worth of some of the philosophers, to their true teaching of the soul’s immortality, and quotes Horace’s “Oderunt peccare boni virtutis amore.”