Tolerance, through time, especially since the times of religious wars of the 17th and 18th century, has been one of the most important and challenging philosophical, political and religious issues. Tolerance is intertwined with other components of modern life such as democracy, civil society, and freedom of speech, and it has become an inseparable part of it. Regardless of public and academic interest in this subject, however, tolerance is still an underdeveloped subject-when it comes to its definition and typography. This research was conducted with a comparative-analytical approach, and, after a brief discussion of its terminology, offers a comprehensive exploration of tolerance. In this article, according to different eras of thinking and religion, a new compartmentalization for tolerance is offered. Furthermore, this article examines the vague status of tolerance in political and social context of Iranian society, and, consequently, puts forth the claim that this ambivalence in the definition of tolerance leads to scientific impreciseness in its application.