NOTES 39 The second proposition is the gradual disappearance of the difference between the two systems as a result of a mutual drawing together: the stress is laid on reciprocity. Bourgeois ideologists have previously claimed that a capitalist 'regeneration5 is taking place in the Soviet economy, but this has never gone as far as the convergence theory. Only those economists and sociologists may be classed as proponents of the convergence theory who maintain that while the socialist system is gradually acquiring some of the features of capitalism, the capitalist system is also coming more and more to resemble socialism. The third is the far-reaching conclusion regarding the tendency towards a merger of the two systems, their transformation into a single socio-economic system of a 'mixed' type, which synthesizes some features of modern capitalism with elements of socialism. . In his Theoretial Economic Systems, A Comparative Analysis published in 1958, Walter S Buckingham, an American economist and one of the founders of convergence theory, writes that one of the main conclusions of his study was that the actual functioning economic systems were growing more similar than dissimilar. Among the advocates of convergence theory the most energetic and consistent is Jan Tinbergen, the Dutch economist. In 1961 he published an article entitled "Do Communist and Free Economists Show a Converging Pattern?" His answer to the question was in the positive. In 1965, Tinbergen produced a new series of articles on the subject, which were published in the Belgrade journal Medunarodna Politika. In these articles he reached the conclusion that "both systems are developing and that many of the changes occurring in them show a converging pattern.}> He even claims it can be argued that "both systems are moving towards a system which is better than pure capitalism or pure socialism in the accepted sense of these terms." Two Variants The convergence theory has two variants. One is the economic variant, which is based on the thesis that the two economic systems are gradually drawing closer and that the differences between them are disappearing* The other is the sociological variant, which holds that not only the economic but also the social systems, including the entire range of economic, political and other social relations, reveal this trend towards mutual drawing together and eventual merger into a single system. The most prominent advocates of the sociological variant are Raymond Aron of France and Pitirim A Sorokin of the United States. Aron, the author of many sociologocal studies, writes in his Eighteen Lectures on Industrial Society that the socialist and capitalist systems are two variants of an 'industrial society5 and that both are gradually drawing closer to each other. In another book he expresses the view that ^all industrial societies will in future grow more and more alike but the resultant universal society will hardly have to make the radical choice between