Free-will is one of the complex issues in metaphysics in its particular sense, especially the free-will of the most high Necessary existent, which is seemingly incompatible with the considering realization of the act from Him as necessity; That is, if He is a free agent, His act must not be necessary, and if His act is necessary, then He must not be a free agent. The necessity of the act entails being a free agent, not being a free-willed agent. Islamic Philosophers have presented similar and different views about the criterion of freewill, whether the free-will is in humans or in the most high Necessary existent. Allameh Tabataba’i is one of these philosophers, who has specified apparently different criteria in this field in his works, but the study and analysis of these criteria lead to the conclusion that all of them are different expressions of the same criterion: the agent is bound neither to action nor inaction, or the agent’s equal freedom in choosing action and inaction, which is called comparative contingency.