Lately I have been puzzled by the hostility of some of my "politically correct" acquaintances toward Italian culture in general and Christopher Columbus in particular. The editorial "The Politically Correct Columbus," June 24, corroborates my suspicion that movements now exist to demean the Brave Navigator, and other intrepid explorers of the New World, by absurdly dismissing them as "greedy imperialists."As the author points out, such a limited view of history ignores all sorts of complexities. Behind much of it is the troubling notion that civilization is bad and oppressive, while its opposite is good and liberating. The brutality in our streets, our soaring illegitimacy rate, the unyielding ignorance and illiteracy of our young people - how many of these problems stem from this one delusion that is continually urged upon us through so many different avenues in our society? Violet M. O'Valle, Arlington, Texas Letters are welcome. Only a selection can be published, subject to condensation, and none acknowledged. Please address them to "Readers Write," One Norway St., Boston, MA 02115.