T-'9ENSION is the most insidious enemy of understanding, and it is inevi. table that the American attitude toward Russian ideas as well as toward Russian affairs should be tense at the present time. The approach to problems of Russian culture, which was tentative and inquiring during and just after the war, has become, after bitter experience with postwar Russian politics, more reserved and more critical. There is no need to urge here the danger of this retreat from knowledge and understanding or to advocate a firm grasp of a problem as the best preliminary to mastering it. Philosophers are attracted to thought not merely because they fancy it as an object or an exercise but because they perceive its power. It is a subtle and pervasive energy, like many of the new forces discovered by modern physics which have controlled, undetected, the operation of the universe and have conditioned human life. Much of the time, however, philosophers must be preoccupied with ideas which have either missed their