There are the old ideas and there are the new ideas, and there are the adherents of each, between whom there exist relations ranging from strife to mutual tolerance. Out of all this there arises an ill-defined problem for the Catholic, whose faith commits him to all truth, however, whenever, and by whomever it is found. Because the problem is seldom adequately posed, few Catholic thinkers really tackle it, so that one has come to expect a Catholic thinker to bear, predominantly, either the modern or the antique stamp. He is either taking into a modern system ‘all that is of permanent value’ in the thought of the ancient world or he is finding a modest niche in ‘thomism’ for the findings of modern science. But compared to what can be done, all this is in the dark. What can be done is to understand the old ideas. And once we are fairly launched on this enterprise we discover that what we are really doing is trying to understand simpliciter, to become more intelligent. The wrestle with Aquinas is a wrestle with one’s own stupidity. And then ‘the problem’ is radically transformed, from a worry to a well-defined and formidable programme of work. This is Lonergan’s approach, and it is the reason for something about him that is immediately striking, his refusal to be given a role in the drama of Ancients versus Modems. To a recent critic who thought he found dangerous tendencies in his Christology he replied with a few tags from Aristotle which the would-be traditional critic was, in effect though not consciously, contradicting.