Just as God's omnipotence and his wisdom are each linked to a particular main problem, so God's goodness (bonitas/benignitas) raises its special difficulty for Abelard – one which he shares with almost every Christian thinker: how is the goodness of an omnipotent God compatible with the existence of evil?

THE PROBLEM OF EVIL

Abelard first discussed the problem of God's goodness and the existence of evil in the Theologia Christiana. Although the work ends before the section which would have covered the subject, at the very beginning of the treatise Abelard anticipates his treatment of the area. Where in the Theologia Summi Boni he had confined himself to a very brief explanation of the Holy Spirit, equated by him with God's benignity, in terms of mercifulness, he now describes it (72: 14–17) as ‘that highest goodness by which he orders each of those things which the highest wisdom has made to the best end, always using even evil things well and miraculously arranging whatever deeds are performed wickedly in the best way’. Abelard adds a series of quotations from Augustine, each to the effect that, whatever evil God allows, he uses well: God creates good natures and arranges evil wills; when the devil uses good natures badly, God uses evil wills well. To these Abelard attaches the two quotations from Plato's Timaeus mentioned in the last chapter, which are central to his argument that God's creation and providence are the best possible and could not be different. And, he adds, not only does God make all things as good as they can be, but also ‘he disposes evil things well, through his highest and incomprehensible devising’.