The present thesis is an investigation into the nature of the democratic and totalitarian ways of life. One of the author's main aims is to use terms that cover at the same time the sociological and the psychological aspects of democracy and totalitarianism. Thus, the term "way of life" is meant to imply a particular social and cultural pattern as well as a particular type of behaviour and personality. The analysis of the process of democratisation of the ancient Athenian community and of modern American, French and British societies led me to the following main ideas: A. Every process of democratisation leads to a flexible society, i.e., to a social structure open to change and novelty, and yet, preserving its own basic character. B. Every proces of democratisation leads to an individualised pattern of life. The economic and political individualism, the religious individualism initiated by the Reformation, the individualism in art and philosophy are various aspects of this basic drive towards individualisation. C. Every process of democratisation is connected with a strong drive towards the rationalisation of the pattern of life. A diminution of the power of tradition, a rational economy, a rational administration and type of authority, a rational mode of thought which counterbalances the power of religion (secularisation) are all characteristic aspects of this. D. The process of democratisation is closely associated with periods of social and spiritual prosperity. In conclusion, the democratic way of life is, at the sociological level, characterised by a flexible, rational, dynamic and individualised social organisation of a group of individuals. The terms used to describe the sociological aspects of the democratic way of life were subsequently transposed to the psychological plane, to describe the democratic behaviour and the democratic type of personality. Thus, it is pointed out that individuals living in periods of democratisation, or in constituted democratic societies have a more flexible mental structure then the individuals living in other types of society. The mental functions dominating the process of adjustment to a democratic world are reason, intellect and intelligence. The particular meaning of these terms is revealed by contrasting the mental structure of such individuals with that of the individuals living in the medieval or the modern totalitarian societies, The individuals living in a democratic world are confident in the power of their mind; their behaviour is conditioned to a rational and "inner" type of social authority which is described as the authority of law, as conscience, or as "constitutional morality". In conclusion, the democratic personality has a strong ego structure, the ego being a general concept which covers all the main individualising functions of the human mind. This type of personality is at the same time the result and the cause of an individualised world. In contrast to democracy, the totalitarian way of life is characterised, on the sociological plane, by a rigid social organisation. The mind of the individuals belonging to a totalitarian world is rigidly organised round one idea or feeling; their behaviour is determined by irrational emotional factors even when at the surface they display a strong tendency towards rationality. Nazism and Communism are two totalitarian ways of life characteristic of our time. Both are rooted in the same state of mind, i.e., in the feeling of insecurity aroused in the members of various national groups, or economic classes, as the result of their failure to adjust themselves to a rational social organisation, or to a dynamic and unstable pattern of life. Nazism is in essence a reaction against an individualised and rational pattern of life and an escape into irrationality. The "emotionalisation" of the pattern of behaviour in every sector of life constitutes its main trait. Thus, the Nazi way of life is characterised by a type of society based on primitive emotional bonds, by an emotional attitude towards authority and by an emotional logic expressed in a mythical kind of thought. Communism solves the same basic problem of contemporary man in a different manner. The need for security manifested in the modern working classes, and in certain sections of modern Russian society, has led, not to an escape into irrationality, but to an excess of rationalisation. An excessively rational economic and social system and a rigid pattern of historical development are the main aspects of this. A new type of consciousness - class consciousness - appears which is the instrument by which the Communist type of man organises his world rigidly according to the schemes of a rationalistic conception of life. The thesis presents a comparative study of the democratic and totalitarian ways of life rather than the study of democracy and totalitarianism in themselves. Generally speaking democracy can be regarded as the individual's and group's adjustment under conditions of leisure, totalitarianism as the individual's and group's adjustment under conditions of stress. The factual data on which this study is based are furnished by the analysis of various democratic and totalitarian civilisations, supplemented by the results of a series of recent psychological researches based on questionnaires, interviews and clinical observation.