Pareto's ambitious effort to lay the foundations for a scientific sociology was framed and very much influenced by the epochal events circumscribing his lifetime and that of his nation. As Sammy Finer remarked in 1966, in introducing selections from his writings, he “was born in 1848, the annus mirabilis of liberalism. He died in 1923, ten months after the Fascist March on Rome.” The son of a wealthy Italian nobleman who had been forced to flee temporarily to Switzerland because of his republicanism, Pareto was educated as an engineer, following in his father's footsteps, became a businessman strongly in favor of free trade, and then left Italy to become an academic economist, succeeding Léon Walras at Lausanne. By the turn of the century, he had grown cynical toward democracy, blaming it for Italy's move to protectionism, and leery of the rising influence of Marxism. He set out to design a new science of society built on the premise that political ideologies are not, as Marxists claimed, expressions of class interest, but rather rationalizations (“derivations”) of drives (“residues”) motivating minorities of the most able who use them to mobilize irrational masses. Mussolini welcomed this analysis as a prescription for fascism, which he (and Giovanni Gentile) thought of as a meta-ideological myth to be used to manipulate popular emotions to favor the totalitarian state. Pareto had nothing to do with the fascist movement and loathed both political repression and the anti-Semitism unleashed in the Dreyfus affair.

In the several decades following his death, Pareto came to be thought of as one of the “New Machiavellians,” a charter member of the doctrinal trinity of “Mosca, Pareto, and Michels,” whose work seemed to show that elite rule and mass irrationality were inescapable realities. Mosca was said to have invented the idea of the inevitability of political elites (though he actually used the term “political class”), Michels to have buttressed the thesis with his “iron law of oligarchy,” and Pareto to have introduced the idea of the “circulation of elites” to explain how they perpetuated themselves by cooptation or lost out to rising challengers. Given the rise of plutocracy in the liberal West and mass-party-based dictatorships under fascism and communism, their thinking was bound to command attention, at the very least, and assent from those who shared Pareto's skepticism about progressive beliefs.

This study sets out to rescue Pareto from confinement to this ideological time warp and put him alongside Weber, Durkheim, Simmel, and other classical contributors to the theoretical and empirical study of society. Pareto is already held in high regard by economists, as one of the founders of mathematical economics and the effort to define states of equilibrium, and for providing such formulas as “Pareto optimality” (the condition in which no allocation can be made that would make one individual better off without leaving another worse off). And, as Marshall recognizes, Talcott Parsons drew upon Pareto to give sociology the specific task of studying the influence of what Pareto called “non-logical thinking,” to complement the “rational-actor” approach of economics—a contrast later examined critically by Brian Barry in Sociologists, Economists, and Democracy.

For Marshall, however, this general appreciation does not do justice to Pareto's specific insights into political psychology. He tries to show here that although Pareto's own presentation of his theory “is littered with rather unfortunate, slapdash references” to the way the drives and rationalizations he identified manifest themselves (38), the theory can be restated in ideologically neutral terms and used empirically, in this instance to account for differing attitudes among contemporary British politicians. (No less unfortunately, Marshall alludes to so many other scholarly efforts as to make the text a pedantic obstacle course, obscuring the thread of his own argument.)

The gist of his argument is that Paretan psychology, by elaborating Machiavelli's famous assertion that a prince must imitate the lion and the fox, provides a compelling and useful tool of analysis. For Pareto, these two metaphors reflect tendencies within society as well as among individuals. Although he identified six classes of “residues,” he focused especially on two that reflect the Machiavellian distinction. Thus, “class 1 residues” are those of the lion, reflecting the “instinct of combination”—in politics an aggressive, power-seeking way of creating new groupings and institutions. Class 2 residues aim at “the persistence of aggregates”—that is, conserving the status quo. Lions rely on force, foxes on cunning or craftiness. In business, entrepreneurial speculators are lions, out for conquest in high-risk adventures; rentiers are foxes, risk-averse and content with incremental but sure gains. (Their interaction helps explain the business cycle: “speculators drive the expansion and eventual exhaustion of socially available capital within the consumer economy; once no further potential for capital expansion exists, rentier ‘thrift’ drives the ensuing process of capital contraction and consolidation to start the economic cycle afresh within the capital-producing economy,” 27). Politically, the metaphor of the lion accounts for liberal tendencies, that of the fox for conservative tendencies.

To test the utility of the theory, Marshall conducted a very elaborate two-stage study. First, he developed a scale measuring personality traits, using data from questionnaires to undergraduates. Then, after refining the scale, he applied the findings to a questionnaire which he circulated among Labor, Conservative, and Liberal MPs. The scale essentially groups attitudes along a continuum from lion to fox but simultaneously allows for a great deal of differentiation by age, rank, and so on. Drawing upon numerous previous studies, it measures attitudes regarding value relativism, openness, tolerance toward opponents, nonconformism, postmaterialism, caution and innovation, distrust, and sensation-seeking. The findings were that “Pareto's model appeared validated by the general contrast found between the risk-averse, uncreative conservative and the risk tolerant innovative liberal” (155). Marshall quickly adds, however, that “a great deal of caution” is advisable in interpreting the findings. For one thing, the student study “disconfirmed” Pareto's idea that force and fraud are alternatives rather than presumably complementary tactics. For another, the findings were also probably influenced by the political fortunes of the various political parties at the time the survey was taken.

These meager and hardly counterintuitive results invite more than just caution. Like so many survey questionnaires, those addressed to the politicians often pose vacuous statements open to myriad interpretations. (One example: “Politicians should be motivated by a desire to uphold traditional moral values.”) The simple idea that liberals are innovators and conservatives defenders of the status quo is appealing in some respects but hardly in all: liberals sometimes cling to established practices, such as public programs, whereas modern conservatives are all for bold new experiments in privatization. James MacGregor Burns suggested plausibly that FDR was such a successful politician because he combined the traits of lion and fox. Since Marshall teaches at Glasgow University, he will not be altogether shocked to learn that in assessing this effort to show the strength and utility of Pareto's psychology, at least one reader arrives at a Scottish verdict: Not Proven.