Sub-titled ""A Decade of Modern Conservatism,"" this book by a conservative Dartmouth professor is an account of development in conservative thought during the past ten Years. The author takes the founding of National Review. by William Buckley in 1955 as the beginning of what he calls the conservative ""intellectual resurgence"" in this country. Indeed throughout his book he relies on articles published in the National Review and on the works of the writers on the N.R. masthead to enforce his contention that there is an intelligent and sound alternative to the revolutionary Left and to an increasingly fragmentary liberalism. In chapters dealing with tenets of liberalism, the Negro problem, the origins of a ""dialectical conservatism,"" the political situation in the universities, and prospects for a strengthened conservatism, Mr. Hart expounds the theory and the ideological differences between such conservative spokesmen as James Burnham, Russell Kirk, Frank Meyer, Willmoore Kendall, William Buckley and various other contributors to this magazine. He presents their position on Vietnam, the Supreme Court, the U.N., and the situation of the American Negro. (Hart's mere statement of the problem in this case--""conservatives seem to be asking the Negro to achieve equality in the same fashion as the other ethnic groups in America"" is an example of why Mr. Buckley's fellow travelers are held in such intellectual disrepute by more knowledgeable observers.) As if to compensate for the treatment of his colleagues by leftist writers, Mr. Hart is at pains to point out the erudition of N.R.'s contributors and to display examples of William Buckley's wit. This effort will doubtless prove very soothing to conservatives. As for Mr. Buckley, his entertainment value has never been in question.