The position of Thomas Aquinas in history is determined by the fact that he is the greatest of the scholastic philosophers. What his master and other earlier thinkers had attempted, he more nearly did than ever has been done by any one else. He took the two great bodies of knowledge, secular and sacred, and fused them into a system more nearly consistent with itself than any other. On the one side was the encylopaedic philosophy of Aristotle, and the parallel but less perfect tradition of Platonic speculation; on the other the Scriptures, the dogmatic decisions of the councils and popes, and the teachings of the recognized authorities among the ecclesiastical writers, especially as these had been summarized by Peter Lombard. To blend these into one great system of theology, to subsidize the weapons of the Greek philosophy in defence of Christian truth, and to draw the line with accuracy between what reason can prove and faith accepts without proof—this was what he undertook in the _Summa_. And never was a more acute intellect employed on the great task of reconciling faith with reason. If he failed, it is not because he shrank from anticipating any and every kind of objection to the truths he was defending; his works are a perfect storehouse of such objections. If he failed, it was not from any want of confidence in the powers of the human mind to deal with the highest subjects of thought. No modern rationalist ever surpassed him in that respect. He failed because neither then nor now do the materials exist for such a work, and because his truths lost and his errors gained force by being worked into a system. It would take a whole chapter even to describe the _Summa_. Of its three parts, the first, concerning God, and the second concerning man, were completed in the four years he gave to the work. In the third, which treats of the God-Man, he got no farther than the ninetieth question, and the discussion was completed by extracts from his commentary on Peter Lombard. But the completed part contains nearly _two million_ Latin words, or with the supplement, two million one hundred thousand. It is six times as large as Calvin’s _Institutio_, or four times as large as the Latin Bible! And the _Summa_ fills only two of the seventeen folios of his works, all written within the space of twenty-six years by a man actively engaged in teaching, lecturing, and advising popes and princes.