Flann O’Brien’s The Third Policeman is a novel grounded in a period of scientific upheaval. As a result scientific subjects, from Einstein‚’ special relativity to industrialization, pervade the novel. By utilizing these themes, the text explores the way empirical knowledge functions as a defining element of human understanding. This paper will argue that O’Brien humorously represents empirical methods of knowledge to convey how methodological epistemology fails to structure an understandable reality. This is apparent from the way the text utilize images of science and structures its language. Science is often shown in the text as a means to achieve absolute knowledge. However this same knowledge fails to have practical implications as it becomes self-referential and thus meaningless. In a similar manner the language used in the novel comically employs various registers, most notably the scientific, to create an obstructive text. The language of the text is often opaque and uses abundance of information to convey the futility of defining reality through speech. By utilizing these themes the author creates a text that is ultimately a parody of encyclopaedia. The Third Policeman depicts a world that revolves around the character of De Selby and his theories. But this conceived world does not coalesce into the same understandable whole De Selby proposes; the hellish parish is an illogical landscape that rebuffs attempts of stable classification. As such, the novel represents an attempt to unify reality into a conceivable object and by this conveys the limitations of such attempts and their inevitable absurdity.