This thesis analyzes the philosophical origins of dualism in Western culture in the Classical period in order to examine dualist modes of representation in the history of Western portraiture. Dualism - or the separation of soul and body - takes the form in portraiture of the representation of the head or head and shoulders at the expense of the body, and since its emergence in Classical Greece, has been the major influence on portraiture. In this respect the modern portrait's commonplace attention to the face rests on the dualist notion that the soul, and therefore the individuality of the subject, rests in the head. Art historical literature on portraiture, however, fails to address the pictorial, cultural and theoretical complications arising from various forms of dualism and their different artistic methodologies, such as that of the physiognomy (the definition of personality through facial characteristics) in the 19th century. That is, there is a failure to identify the complexities of dualism's relationship to the traditional honorific aspects of the portrait (the fact that historians are inclined to accept at face value the fact that portraits historically have tended to honour the achievements and social status of the sitter). Indeed, scholars have a propensity to romanticise the humanist individualists inherent to this long history of the honorific, particularly in canonic portrait practices such as Rembrandt's and Picasso's.