Logic and the explanatory potential of a very influential, for decades already, Raymond Aron’s paradigm of industrial societies and its fundamental standpoint presenting the party system form as a “basic principle” of modern political regimes (systems), as a “main variable” of analysis and as a formula for “deciphering” its nature and legitimacy, are being considered in the context of four basic differences between “constitutional-pluralistic regimes” and “regimes of a monopolistic party”. It is about controversies: 1) between competition and monopoly; 2) constitutionality and revolution; 3) pluralism and bureaucratic absolutism and 4) between a State of Parties and a Party State. Within the abundance of author’s thoroughly differentiated analysis of modern history and politics, Aron’s hypothesis about the “primacy of politics” is interesting also because it was based on critical valorisation of heuristic capacities of several, most familiar historical schemes, including the idea of incorrectness of a one-way development or “end of history”. In other words, this means that the level of economic development, tradition and culture also have an effect on the character of political institutions, which this author in concern articulates with a conclusion reading that “various phases of economic development, more or less, give preference to particular regimes”, and that “it is possible to imagine the developed industrial civilization with different political regimes as well”.