Abstract : The aim of this dissertation is to contribute to a critical review of the theories of expression in art. The foci of this work are visual arts, especially, the painting and the photography. The aim of this work is to understand how a work of art communicates an inspired idea of the artist to the beholders in a non-verbal way. We presume that the pictorial presentation is a primary form of non-verbal expression of aesthetic feelings, and that its intersubjective communicability is based essentially on its formal elements, such as colors and lines, which Clive Bell calls “significant forms,” and which Susanne Langer calls “symbolic forms.” They are considered to be the visual entities that communicate neither with concepts nor with propositional contents. The problem of artistic expression is then treated as a triangular relation between (1) the artistic creation, thought to be an act of expression, (2) the aesthetic feeling, considered to be the motivational condition of (1), and the meaningful content of (3) the significant form, considered to be the relevant property of the work of artistic creation and the vehicle of the aesthetic feeling. Our strategy to resolve the problem of the communicability of artistic expression is to relocate the question in the theoretical context of aesthetic judgement. Our work is then to interpret this triangular relation in terms of the formation of the judgement of taste, the expression of an aesthetic feeling, and the perception of the aesthetic property that we situate in a theoretical framework of affect-cognition interaction. We defend a conception of aesthetic realism on the basis of the scientific realism of affectivity, such as the James-Lange theory and the appraisal theories of emotion, whereupon we claim that the affective properties are real, in that they are the properties about the body of the perceiving subject, and that the truth conditions of the judgement about them are to be the neurophysiologic states of the body, observable and verifiable by functionalist approaches, and by empirical methods. In a weaker sense, an emotional state is the state of the mind of which the features may be simulated using computational modelling techniques, as it is suggested in the appraisal theories of emotion. The experience of emotion is then considered either to be the perception of the bodily state of which the reality is as unquestionable as the perceived world, or to be a functional modality of the mind. On the basis of the latter, or more specifically, on the basis of the appraisal theories of emotion, we put forward a model of aesthetic appraisal that helps in explaining the processing of the perception and the evaluation of a work of art and in studying the processes of the “making” of an aesthetic judgement. We would like to show that both the affective/aesthetic stimulus (the work of art) and the perceiving subject (the artist and the spectator) constitute a complex interactive system and that there shall be a stable correlation between the physical properties of the stimulus and the physiological-emotional reactions of the perceiving subject. Our aim is to look for the relevant perceptual variables that determine the subject's affective reaction to the work of art. We consider them to be the aesthetically relevant and visually salient features of the stimulus, such as the degree of contrast, the figure-ground segregation, the direction of pictorial composition (vertical, horizontal, or diagonal), the relation of center-periphery in the pictorial field. The model is aimed to illustrate the relation between the physical (perceptual) properties of the work of art and its affective/aesthetic/evaluative properties. Like scientists of emotion who work for developing theoretical models to explain how different emotional contents should be produced and differentiated by distinctive appraisal patterns determined by the combination of specific cognitive, appraisal and motivational components, we put forward the model of aesthetic appraisal in order to determine the variables of aesthetic judgement, as well as to explain the reason why the aesthetic object is said to be beautiful or sublime, why it is gracious or elegant in such conditions, and why it is not so in other conditions.