In 1980, when Ronald Reagan won the U.S. presidency in a 44-state landslide, academics at Dartmouth College were so incensed by the electorate's perceived misconduct that a faculty meeting passed a formal motion condemning it.

Though not mentioned in the book under review, this absurd incident exemplifies the problem with which it deals. Indeed, the book contains evidence that since the 1980s the ideological imbalance in American universities has increased, giving liberals -- along with those left of liberal -- an overwhelming numerical advantage over conservatives. The imbalance is especially extreme in such departments as history, psychology, sociology and English literature. In one survey more than a quarter of the respondents in sociology classified themselves as "Marxists," as did more than 17 per cent in the social sciences as a whole. Departments of economics appear to be intellectually more diverse, but not sufficiently so for advocates of a free market to achieve anything close to parity.

In this environment, even academics who portray themselves in surveys as "middle of the road" or "right of centre" may be giving the terms a meaning different from those attached to them in normal political discourse. In the opening chapter, Larry Summers (treasury secretary under Bill Clinton) is quoted as saying that in Washington he was on "the right half of the left," whereas at Harvard -- where his term as president was cut short by controversy -- he was on "the right half of the right." In the eyes of those who regard the legitimate political spectrum as extending from Karl Marx on one side to Barack Obama on the other -- Summers now serves in the Obama Administration -- true conservatives may be relegated to a frightening zone of darkness, the habitat of imagined monsters.

Problems of political terminology are only one of many complexities with which contributors to this book must contend. The sixteen chapters -- the work of various authors or teams of co-authors -- focus on topics ranging from the damage inflicted on particular disciplines (history, English and political science, the last of which has apparently suffered least) to an argument that trustees and alumni can and should prevent repressive professors from improperly exploiting their academic freedom to curtail the academic freedom of students and dissident colleagues.

In Chapter 7, Peter Wood -- president of the National Association of Scholars -- examines the threat posed to "diversity of ideas" by the "idea of diversity," which he calls "an aggressive ideology that stigmatizes and attempts to drive out anyone who does not actively support it." Diversity in this sense -- meaning collective entitlements for "victim" groups -- is a logical consequence of liberal thought. The author might have cited Kenneth R. Minogue's book The Liberal Mind (published in 1963). Writing before the current obsession with "diversity" developed, Minogue pointed out that ideological liberals (like Marxists) divide society into suffering "victim" classes on the one hand and "oppressors" on the other. Moreover, if they belong to perceived "oppressor" classes, such as the white race, liberals experience a sense of shared guilt that impels them to do something to make amends, and to separate themselves from the "guilty entities." Thus the underlying motivation for "diversity" may be less to assist the favoured minorities than to make the enforcers of group preferences feel better about themselves -- a possibility raised explicitly by William O'Donohue and Richard E. Redding in Chapter 6 of the volume under review.

Why have liberals and the far left been able to achieve such supremacy? In Chapter 3, by Matthew Woessner and April Kelly-Woessner, we find evidence that the academic performance of conservative students is very similar to that of liberals, while "moderates" do less well than either. But, although there appears to be a correlation between political commitment and greater academic ability, conservatives are less likely than either liberals or moderates to seek the doctoral degree normally required for an academic career. Conservatives seem to have other priorities, such as starting a family and making money. To some extent, therefore, the paucity of conservative professors may result from self-exclusion rather than discrimination; but that explanation is less than fully adequate. In Chapter 6, for example, we are told that "conservative students may feel alienated when few (often none) of their professors share or respect their views and when conservative perspectives are excluded from pedagogy."

Moreover, conservatives may have realistic fears that the "groupthink" examined in Chapter 5 (by Daniel B. Klein and Charlotta Stern) would impair their prospects for success in the academic job market; the authors explain how the principle of majority rule within departments enables a small ideological majority to become over time a larger majority, simply by hiring only (or mostly) those who share the dominant orthodoxy.

It is not exclusively in universities that left-of-centre opinion prevails to an extent far exceeding its support among the public. American conservatives have long made the same complaint about other "elites" -- those of Hollywood and the "mainstream" media. It would have been interesting to see an essay placing the political leanings of the academic world in this wider context. It might also have been desirable in places for authors to use a livelier literary style, more appealing to the general reader. In Chapter 6, for instance, we read that some of the people who claim to be "offended" by something or other "may be psychologically constituted in problematic ways." I think this means that they may have psychological problems, or (more colloquially) that they may need to have their heads examined -- an impression confirmed by the unattractive "personality disorders" that O'Donohue and Redding go on to describe.

One further criticism: Supporters of the Foundation for Individual Rights in Education may be disappointed by the book's failure to recognize the value of FIRE's efforts, through publicity and actual or threatened legal action, to defeat "speech codes" and other repressive manifestations of the "politically correct" mentality. The admirable American Council of Trustees and Alumni is treated more fairly, since its president, Anne D. Neal, is the author of Chapter 14.

These are relatively minor points. The book makes an important contribution to our understanding of what has gone wrong in higher education. Some chapters include proposals for reform, such as the creation of new academic units outside the control of entrenched departmental majorities, to pursue the study of "politically incorrect" subjects like Western civilization and the institutions associated with political and economic freedom. In a few universities units of this kind have already been successfully established, but the road to comprehensive reform will clearly be long and difficult.