KNOWLEDGE but it seems inadequate in two ways First of all, we think with assent whenever we call to mind a belief on any topic, whether religious or not Secondly, as Augustine himself often points out, at any moment there are many things we believe even though we are not thinking about them at all A thought, that is to say a thinking (cogitatio), is a dateable event in our mental life; belief (including the special kind of belief that is faith) is something diVerent, a disposition rather than an episode When Augustine talks of faith, he is less concerned to expound its epistemic status than to emphasize its nature as a gratuitous virtue, one of the Pauline triad of faith, hope, and charity, infused in us by God And when he is most eloquent in expounding its role, his language once again uses the metaphor of light, but in a manner that goes contrary to his explanation of our knowledge of eternal truths Thus, we read in The City of God, ‘The human mind, the natural seat of reason and understanding, is enfeebled by the darkening eVect of inveterate vice It is too weak to bear, let alone to embrace and enjoy, the changeless light To be capable of such bliss it needs daily medication and renovation It must submit to be cleansed by faith’ (DCD IX 2) Bonaventure on Illumination The relation of faith to reason occupied a principal place in the epistemology of Augustine’s successors in the high Middle Ages St Bonaventure, like Augustine, preferred Plato’s philosophy to that of Aristotle, but he believed that even Plato’s greatest successors, Cicero and Plotinus, were grievously in error about the true nature of human happiness Without faith, no one can learn the mystery of the Trinity or the supernatural fate that awaits humans after death (I Sent 4) But, for Bonaventure, the philosopher, however gifted, is in a position worse than that of mere ignorance: he is in positive error about the most important things there are to know ‘Philosophical science is the way to other sciences; but he who wishes to stop there, falls into darkness’ (De Donis, 12) A Christian philosopher, enlightened by the grace of faith, can make good use of the arguments of philosophers to broaden his understanding of saving truth This Bonaventure himself does, oVering various proofs of the existence of God: defective being implies perfect being, he argues, 162