Much work has been done on the epistemological teaching of Thomas Aquinas. There have been efforts of real scholarship and intellectual penetration to evolve some sort of synthesis between the critical problem as commonly proposed and the Thomistic metaphysical approach which appears remarkably indifferent to any such problem.¹ Of all the solutions proposed, there is no one which appears to fit the facts better than the explanation which has been expounded in American circles by Maritain,² Gilson,³ and Regis.⁴ It alone seems to find actual textual confirmation, so much so that it has become almost platitudinous to assert that the ontological approach to knowledge which is characteristic of Aquinas precludes the formulation of the modern critical problem. However, there is still a great deal of controversial discussion regarding the textual support of this position. Argumentation has revolved for the most part upon the general metaphysical principles implicit in the seizure of being. This is certainly the direction in which a valid demonstration must be pointed. However, for purposes of cogency and precision, I think that another, supplementary approach would be to narrow these general metaphysical principles, of which we shall have something to say later, to a more precise circumscription of this problem of knowledge in its proper psychological setting. When this is done, the solution becomes evident.