The elite theories of Gaetano Mosca, Robert Michels, and Vilfredo Pareto, developed in the late 19th and early 20th centuries, fundamentally challenged liberal democratic ideals by asserting the inevitability of minority rule.

Similarities:
Their most crucial common issue is deep skepticism about genuine democracy. All three argued that power always concentrates in the hands of a small, organized minority (the elite), with the vast majority remaining passive and ruled. They rejected popular sovereignty as an illusion, seeing history as a perpetual struggle between different elites, not a progression towards mass rule.

Differences and Main Issues:

1. Gaetano Mosca (The Ruling Class):

   • Main Issue: Superior Organization and "Political Formula." Mosca believed elites rule primarily due to their high organization and ability to coordinate action, contrasting with the unorganized masses. They legitimize power through a "political formula"—a set of beliefs or myths (e.g., divine right, popular will) that convinces the masses of their right to govern.

2. Vilfredo Pareto (Circulation of Elites):

   • Main Issue: Psychological Traits and Elite Circulation. Pareto focused on the psychological qualities of individuals, categorizing them into "Lions" (forceful, conservative) and "Foxes" (cunning, manipulative). Elites maintain power by possessing a balance of these traits. When an elite becomes too one-sided or loses vitality, it is eventually overthrown and replaced by a new elite through "circulation of elites," preventing stagnation.

3. Robert Michels (Iron Law of Oligarchy):

   • Main Issue: Organizational Necessity Leads to Oligarchy. Michels, studying socialist parties, argued that even democratic organizations inevitably become oligarchic. The scale and complexity of modern organizations necessitate specialization and bureaucracy, concentrating power in a few leaders. These leaders become indispensable and self-serving, forming an oligarchy. His "Iron Law" states, "who says organization, says oligarchy."

In essence, while all agreed on elite rule, Mosca highlighted organizational superiority, Pareto emphasized psychological composition and elite replacement, and Michels pinpointed inherent organizational dynamics leading to oligarchy.