Quaeritur: I found the following statement in an article by John Vennari on Modernism: "Bishop Sigaud lamented that Thomism is being displaced by the dangerous modern philosophies of Jacques Maritain."
Isn't Maritian one of the three 20th-century philosophers you said were good Thomists?
Respondeo: The three 20th-Century philosophers at the top of my list are:
a) Fr. Reginald Garrigou-Lagrange, O.P.;
b) Fr. Santiago ("Jacobus") Ramirez, O.P.; and
c) Fr. Edouard Hougon, O.P.
But Maritain was undoubtedly a good Thomist in many respects; in fact, for his traditional approach to Thomism, he is seen as one of the most famous Thomists in the last century. But there is a question whether he was totally orthodox.
I would say, with Garrigou-Lagrange, that he wasn't totally orthodox. He may have been partially infected by modernism ub some areas. (Perhaps this is what Mr. Vennari had in mind: that he was a modernist, not that he wasn't a Thomist. After all, a "modernist Thomist" is not only not an oxymoron: that, unfortunately, is the best way to describe the majority of Thomists today!) In any case, Maritain's political views are definitely un-Thomistic and questionable (he tries to defend democracy based on Thomistic principles, whereas Aquinas and all of his traditional followers are obviously royalists / monarchists). Also, his aesthetics and "philosophy of mysticism" may also be a bit untraditional and objectionable from the point of view of revelation. Even his writing style and choice of expressions are a bit loose, un-Scholastic, and overly-existentialistic for the likes of a traditional Thomist.
However, the conceptual content in his metaphysical and epistemological works is nothing but sound, standard, traditional Thomism. He is also unique among Thomists because he is a convert; he was a non-Thomistic philosopher in his youth and his encounter with Thomism attracted him towards the Church. In his writings, when refuting all of his previous errors, he could look at things from a unique "insider's perspective." His best-known epistemological and metaphysical book is The Degrees of Knowledge. It is a very thorough and sophisticated Thomistic discussion of human knowledge. Even Garrigou-Lagrange (who was unquestionably the best Thomist of the last century, and also Maritain's spiritual director at somepoint) commends Maritain for his metaphysics and epistemology and even cites him approvingly in his own works.
However, once Garrigou became aware of Maritain's liberal political views, he advised him to stay away from political philosophy and to dedicate his time to his metaphysical epistemological issues. (A book that summarizes the relationship between these two famous Thomists is The Sacred Monster of Thomism by Peddicord; there, it is said that, when Maritain, the convert, tried to persuade the super-traditional Garrigou-Lagrange about democracy, Garrigou felt indignant and said something like, "you are now going to lecture us, who have been Catholic for 300 years, on a new Catholic social doctrine?!") This caused animosity between the two--actually, on the part of Maritain, rather than on the part of the saintly priest--which resulted in the end of their spiritual meetings and their friendship altogether. Maritain expected Garrigou to apologize, but he never did.
Truth over human friendships.