Discouraged by the ways in which the perspectives of different people, classes, eras, cancel one another, you may decide that all philosophies are nonsense. Or you may establish order by fiat, as you bluntly adhere to one faction among the many, determined to abide by its assertions regardless of other people's assertions. Or you may become a kind of referee for other men's contests, content to observe that every view has some measure of truth and some measure of falsity. If they had asserted nothing, you could assert nothing. But in so far as they assert and counterassert, you can draw an assertion from the comparison of their assertions.

Professor Karl Mannheim's "sociology of knowledge" is a variant of the third of these attitudes. He would begin with the fact of difference rather than with a choice among the differences. But in erecting a new perspective atop the rivalries of the old perspectives, he would subtly change the rules of the game. For the new perspective he offered would not be simply a rival perspective; it would be a theory of perspectives. In so far as it was accurate, in other words, its contribution would reside in its ability to make the perspective process itself more accessible to consciousness.

Faction A opposes Faction B. To do so as effectively as possible, it "unmasks" Faction B's "ideology." Faction B may talk nobly about "humanity" or "freedom," for instance. And Faction A discloses the "real meaning" of these high-sounding phrases in terms of interests, privileges, social habits, and the like. Faction B retaliates by unmasking Faction A's ideology.

Each faction exposes, as far as possible, the conscious and unconscious deception practiced by the ideologists of rival camps. But in the course of exposing the enemy, a faction comes upon principles that could be turned upon itself as well. Hence, it can spare its own members from the general censure only by "pulling its punch." And precisely at this point there enter the opportunities for a "sociology of knowledge," if only the sociologist can so change the rules of the game that he finds no embarrassment in completing and maturing this "unmasking" process.

This he does in the easiest way imaginable. Whereas the ideologists of the opposing factions "point with alarm" to the fact that there is a difference between the face value of an opponent's idea and its real value in social commerce, the sociologist starts out by taking such discrepancies for granted. He begins with the assumption that an idea must be "discounted" by the disclosure of the interests behind it. Hence, he can treat the difference between the face value of an ideology and its behavior in a social context not as an "unmasking" but as an "explanation" or "definition" of the ideology. Thus, instead of being startled to find that an idea must be discounted, and taking this fact as the be-all and end-all of his disclosures, he assumes at the start the necessity of discounting, and so can advance to the point where he seeks to establish the principles of discounting.

Such, at least, is the reviewer's way of understanding Professor Mannheim's point in tracing a development from the "unmasking of ideologies" to the "sociology of knowledge." And his [Ideology and Utopia] presents a great wealth of material to guide the sociologist who would define ideologies in terms of their social behavior. Incidentally, in his gauging of the case, he suggests reasons why members of the intelligentsia are not a perfect fit for strict political alignment. Their working capital is their education—and in so far as they accumulate this capital to its fullest, they venture far beyond the confines of some immediate political perspective. He does not use this thought, however, to disprove the value of political affiliation. On the contrary, he suggests that there are ways in which this somewhat "classless" ingredient in the "capital" of the intelligentsia may serve to broaden and mature the outlook of the stricter partisans, and enable them to take wider ranges of reality and resistance into account.

As for the key terms, ideology and utopia, their "discounting" in social textures makes it impossible for the reader to follow them as absolute logical opposites. In general, the term ideology is used to connote "false consciousness" of a conservative or reactionary sort—while utopia stresses the same phenomenon in the revolutionary category. If conditions have so changed, for instance, that the landed proprietor has become a capitalist yet "still attempts to explain his relations to his laborers and his own function in the undertaking by means of categories reminiscent of the patriarchal order," he is thinking by "ideological distortion." And the "spiritualization of politics" in the thinking of the Chiliasts is treated as a typical utopia, surviving even in the thought of anarchists like Bakunin. However, although the conservative is not naturally given to utopian imaginings, being content to accept the status quo, the competitive pressure of revolutionary utopias spurs him to the construction of counter-utopias. Hegel's romantic historicism, erected in opposition to the liberal idea, is given as a prime example. Perhaps the following quotation illustrates the difference most succinctly:

As long as the clerically and feudally organized medieval order was able to locate its paradise outside of society, in some other-worldly sphere which transcended history and dulled its revolutionary edge, the idea of paradise was still an integral part of medieval society. Not until certain social groups embodied these wish-images into their actual conduct, and tried to realize them, did these ideologies become utopian.

The book is concerned with the ramifications and subtilizations of this distinction, and with a theory of knowledge to be drawn from the plot of history as charted in accordance with these terms. The discussion being conducted largely in abstractions, the book will probably not endear itself to the general reader—but anyone interested in the relation between politics and knowledge should find it absorbing. Perhaps we could venture to summarize the case this way: whereas the needs of the forum tend to make sociology a subdivision of politics, Professor Mannheim is contributing as much as he can toward making politics a subdivision of sociology.