Collectivists assert collective interest over individual interest, whereas individualists begin with the recognition of individual interest and accept collective interest as the result of intersecting individual interests.

Individualism is thus not only correspondent with the world as observed, which clearly contains only self-interested individuals with interests that overlap to produce collective interest, but also causally inclusive, since it provides a causal account of collectivism. Individualism can explain collectivism, but Collectivism cannot explain individualism except as aberrant evil.

That is to say, Collectivism is Virtue in Mandeville's sense, a requirement (never fulfilled) for a frustration of human interest, for self-denial. Such positions must, as Mandeville recognised, class all self-assertion as vicious if they are to be robust; no degree of compromise is tenable, all must slide to the extremes. One is either a rigorist, or one denies that the relevant Virtue has any standing.