That so many Christian intellectuals, particularly Roman Catholics, have incorporated Straussian anti-historicism into their thinking is indicative of philosophical poverty as well as gullibility, not to say suicidal tendencies. These Christians appear not to take very seriously that, in addition to Scripture and reason, mainstream Christianity has cited tradition as one of its pillars. Or perhaps these intellectuals simply have not understood that Strauss’s attack upon “historicism” is, among other things, an attack upon tradition. Many Thomistically inclined thinkers seem not even to have noticed that Strauss’s disparagement of convention as incompatible with philosophy runs counter to the close connection seen
by Aquinas between natural law and custom. Aquinas writes that “if something is done a number of times it seems to be the result of a deliberate rational decision.” He senses that the authority of long-standing custom has something to do with its both contributing to and being informed by reason. Though Thomas is far from having Burke’s more consciously historical awareness, his notion of natural law is quite different from Strauss’s ahistorical conception of natural right, which helps explain Strauss’s barely concealed disdain for Thomas as a philosopher in Natural Right
and History. Thomas is not so much a philosopher, Strauss says, as one codifying Christian belief and practice. Thomas’s notion of natural law, says Strauss, is “practically inseparable not only from natural theology—i.e., from a natural theology which is, in fact, based on belief in biblical revelation—but even from revealed theology.”
A point of wider philosophical interest is that many Christians seem not to realize that to accept the Straussian ahistorical notions of philosophy and right is to accept the proposition that synthesis between the universal and the historical is impossible. But to accept such an idea is, among other things, to reject the central
Christian idea of incarnation, the possibility of the “Word” becoming “flesh.” Only lack of philosophical sophistication and discernment could have made so many Christians receptive to a doctrine that strikes at the heart of their own professed beliefs. Some Christian thinkers, including Thomists who are today slowly awakening
to Straussianism’s being in some ways problematic, seem to imagine that as long as they hold to their traditional religious beliefs and practices their Straussian intellectual habits will not do any harm. But to retain the habits of ahistoricism is to contribute to the erosion of Christian intellectual culture as well as to close
off access to some of the most important philosophical advances in human history.
-Claes Ryn, Leo Strauss and History: The Philosopher as Conspirator (PDF)