Architecture is, in fact, the formulation of the relationship between interior and exterior, and this is the most fundamental issue in architecture. The  interaction between interior and exterior includes functional and geographical effects, and cultural and social relations which can be considered as a “relationship” per unit of time. However, the term “symbiosis” refers to the interaction of living things (real or virtual). Architectural “Ontology” in general or the symbiosis of interior and exterior in particular, is a qualitative approach based on human and environmental variables which are, in turn, indivisible, floating and interconnected. Fuzzy methods facilitate such studies by measuring the variables and their relationships. The present study is mainly aimed at clarifying the relationship between interior and exterior spaces in the most famous mosques in Iran through spatial, physical and semantic analysis. The study aims at a fundamental purpose by collecting data from library sources and field research based on a descriptive method with fuzzy analysis. The study results indicate first the efficacy of fuzzy analysis in identifying the components of “interactive region” and explaining the quality of the symbiosis in the architecture of the mosques. Second, the results reveale that the absolute generalization of a concept, as the fundamental principle of the mosque architecture, is to disregard the values which are different from that certain concept in other conditions based on the incompatibility principle of the fuzzy theory, although these values may first appear to be heterogeneous, they are significant at a higher level of insight and considered to be the basis of the identity of any building.