Formal considerations constitute the core aspect of Peter Eisenman's work. Arguably, they are the only consistent theme of his work, and are based on the concept that architecture is a mediation between the embodied internal world of human beings and the external physical world which we inhabit. Eisenman thus gives form a 'conceptual' rather than perceptual basis, whereby universal formal relationships are more important than sensual aspects. This leaves architecture as a syntactic operation based on reason and logic, with apparent formal relationships as is its main justification. The understanding and development of an inherent formal language becomes the main goal in such an approach, and meaning is disregarded in its extrinsic character with a reference to social, historical or other representational traits. In this paper I am discussing Eisenman's views on architectural formalism through the scope of aesthetics. Since he disregarded aesthetic considerations throughout his career, especially beauty, it is fruitful to explore and examine his stance on the properties of architecture as a way to justify his claims of formal primacy. I am basing my analysis on Nick Zangwill's formalist theories, and thus giving primacy to the formal-spatial properties of the architectural object as being judged by the human subject. This could bring back the discussions of formalist aesthetics to architectural theory and makes the judgment of architectural quality a formal issue.