This thesis sets out to place the Modernist revolution in arts in its historical context not by describing contemporary or parallel events, in politics or' technology for example, but by first developing a theory of aesthetic signification which allows different arts to be treated together and, second, by extending this theory in such a way that useful correlations can be made betu/een the practices of aesthetic signification and other areas of social life. The result is that Modernism comes to be seen as a critical aesthetic self-consciousness which is symptomatic of a deep uncertainty as to the relationship between Art and Life and, further, as a transitional phase between artistic practices which assume that relationship to be located in their external references and representations and artistic practices which assume that relationship to be located in their social functions and effects.