This study explores the characteristics of postmodern complexity as a social and aesthetic condition in Turkish fiction. The reflections of this condition are intellectually registered in the novels of Turkish author Hasan Ali Toptas. His selected works are taken as representative of the postmodern avant-garde. Lyotard's reflections on the postmodern condition and the avant-garde are deployed in this analysis - in an extensive interpretation of Lyotard's analytical work, it is suggested that the postmodern avant-garde in the fiction of Toptas represents a creative inquiry into both the form and the content of the novel in terms of possible expressions of the sublime. Toptas's work, it is argued, successfully exposes the ultimate failure in representing the sublime by way of a definite subject. Fragmented, dissolved and traversed by social complexity, no form of subject can adequately represent the sublime. In the postmodern condition, the only possible register of the sublime is complexity itself. The challenge of the imagination is, therefore, to present it to the most adequate extent possible.