Judging from the list of professors in the Philosophy Department of new york University, most of their philosophy professors are world-class philosophers or world-class scholars in their professional fields. The mainstream of American philosophy is analytical philosophy, and almost every professor in its philosophy department is a leader in all branches of analytical philosophy, such as Dworkin, the author of Virtue, the greatest thinker of our time, and Thomas Nagel, a famous philosopher and ethicist. Most of these professors are engaged in the study of the basic problem of philosophy, that is, the basic theory, and have established their own unique theories or doctrines, so they are philosophers in the true sense.