For centuries, the ontological question of representation has plagued the philosophical tradition: does the mind represent the external world? By taking a critical perspective, I will briefly survey the philosophical literature and analyze the usage of representation in modern philosophical and scientific circles, providing a historical context for the ontological question of representation. After determining that modern philosophy and cognitive science is, counter intuitively, moving away from the representational stance, I then look back on the twentieth century and give an examination of the roots of the anti-representationalist paradigm, focusing on the work of Martin Heidegger, James Gibson, and the proponents of dynamic systems theory. Through the use of Heideggerian phenomenological-ontology, I propose an ontological solution to the problem of mental representation. By taking an ecumenical phenomenological approach, I recast the dichotomy between representationalism and non-representationalism into a derivative continuum, focusing on how the phenomena of mental content, and thus representation, only arises in breakdown cases of our normal ontological familiarity. After having contrasted this conception of our Being with the metaphysics of Descartes, I explain how we can avoid dualism while maintaining the phenomenology of "thinking" which has been typical of the philosophical tradition.

The thesis aims to interpret the philosophy of negative Platonism, which Jan Patočka developed during the 1950s. In the first part, negative Platonism, whose preliminary notion is derived from the interpretation of the eponymous programme essay, is studied in the context of contemporary philosophical discussion and Patočka's subjectivist humanistic conception he developed in the latter half of the 1940s as well as his lectures on classical philosophy. The second part contains author's own systematic interpretation of negative Platonism, including the reconstruction of the textual corpus of Patočka's programme. Finally, the third part, which considers first the inspirational sources of the observed project, reviews negative Platonism and outlines a concept, with which Patočka replaced negative Platonism in the late 1950s. The thesis aims to outline the philosophy of negative Platonism as an important stage in Patočka's philosophical development as well as a significant part of the modern history of European thinking.