This thesis considers certain critical moments in the writing about art in modernity. I firstly identify key exemplars as responses to a "crisis of representation" within a broadly conceived discipline of art history in Britain. These mark significant turns in the discipline, one towards a newly invigorated Marxist social history of art in the 1980's and one towards an increasingly philosophical mode of investigating aesthetic works. Whilst the latter can be said to have most impact after the 1980's, key aspects of the actual object of study pre-date this. The exemplars in the first two parts of the thesis are the writing of the British art historian T.J. Clark, principally in respect of his critical work, writing on Manet's painting of Olympia in the article first published in the British journal Screen in 1980 and the writings on the film Hiroshima Mon Amour, a film which dates from 1959 and not only documented by its script writer, Marguerite Duras at the time, but subject to critical readings within film theory and testimony studies in the 1990s, drawing upon particularly modern French philosophical thought. I examine how these exemplars present the relationship between aesthetics and politics but also the extent to which the paradigms by which they think that relation can be shown to come up against their own limits. I consider the challenges these exemplars presented to other modes of disciplinary thinking; Clark's Marxist criticism was part of a major politicisation of the discipline of art history and the film Hiroshima Mon Amour in itself and supported by Duras's script presented a major challenge to documentary and "memorial" cinema. But I argue that they return us to thinking the political or the historical in foundational or other essentialist ways under which the aesthetic is subsumed. It is by way of the philosophy of Jacques Derrida and Jean-Luc Nancy and critical thinkers influenced by them that I have problematised these exemplars. Derrida and Nancy have provided an approach which whilst respecting the criticality of the tradition, shows where that criticality meets its limits and forecloses on its questioning and openness to the potential 'other' in the aesthetic and the political, out of which there emerges a responsibility to continue to think the relation between aesthetics and politics. In addition, to deepen the context through which I invoke Derrida and Nancy and to offer historical insights to inform current critical concerns within the disciplines of art history, the thesis examines the philosophical writings of Martin Heidegger and Walter Benjamin in relation to art and politics and technology written in the 1930s. Heidegger's influence especially is fundamental to Derrida's and Nancy's thought but it is from the contrasting outcomes of Heidegger's and Benjamin's thoughts on art and technology that lessons may be drawn in respect of critical issues for contemporary politics and culture. The final chapter refers to some of these critical issues as part of a re-iteration of the contemporary importance of reading art 'otherwise' in the wake of a perceived waning of relevance of 'critical theory'.