"Nobody, as I have said, says that St. Francis drew his primary inspiration from Ovid. It would be every bit as false to say that Aquinas drew his primary inspiration from Aristotle. The whole lesson of his life, especially of his early life, the whole story of his childhood and choice of a career, shows that he was supremely and directly devotional; and that he passionately loved the Catholic worship long before he found he had to fight for it."
- G.K. Chesterton, Saint Thomas Aquinas: The Dumb Ox, Image/Doubleday, pg. 15.
St. Edith Stein:
"But no matter whether one regards philosophy as a purely natural science -- that is, a discipline resting exclusively on reason and natural experience as its sources of knowledge -- or whether one grants to it the right to draw additional light from revelation, there can be no doubt that the philosophy of the great medieval doctors of the church grew to its maturity in the shadow of Christian doctrine. In revealed truth it saw the measure of all truth, and it made every effort to resolve those problems which were posed by Christian dogmatics . . . .
In this matter modern philosophy has cut itself off completely from the medieval tradition. The question therefore arises whether there is still common ground for constructive intellectual effort between such heterogeneous ways of thinking. St. Thomas Aquinas himself answers this question strongly in the affirmative. His own relationship to Aristotelian and Arabian philosophy presents sufficient evidence that he believed in the possibility of a philosophy founded on pure natural reason, unaided by revealed truth. He clearly demonstrates this conviction in his Summa contra gentiles, commonly known as his philosophical Summa. Here he points out that in discussions with pagans and Moslems, the Christian thinker cannot refer to a common faith based on the Scriptures (a common ground which in the case of the Jews is provided by the Old Testament and in the case of heretics by the New Testament). It therefore becomes necessary, he says, 'to have recourse to that natural reason to which all must assent.' There are, according to st. Thomas, two ways of truth, and though natural reason cannot attain to the highest and ultimate truth, it can nevertheless ascend to a stage of knowledge which enables it to reject certain errors of judgment and to recognize the accord between the naturally demonstrable truths of reason and the truths of faith."
St. Edith Stein, Finite and Eternal Being, translated by Kurt F. Reinhardt, ICS Publications, 2002, pp. 12-13.
Pope Benedict XVI:
"The universal people -- the Church -- is formed through the power of the Holy Spirit as the bearer of the New Covenant. Just as the covenant people is extended and becomes universal, so too the "law" (the contents of the covenant) takes on a new form. What had been only scaffolding and preparation, as it were, can now be taken away. The core of the law is disclosed in the flame of the Holy Spirit, in which God's own essence -- love -- is represented. Thus Thomas Aquinas could say: The new law is the grace of the Holy Spirit (Summa Theologica I-II, q. 106, resp.). Forms of worship and juridical orders, which are necessarily and always particular, recede in importance, and what is truly universal emerges -- grace, which is the love poured out into our hearts by the Spirit (Rom 5:5)."
- Joseph Ratzinger (Pope Benedict XVI), On the Way to Jesus Christ, Ignatius Press, 2005, pp. 134-135.