This article is the first part of a collection of articles about fundamental views of Allameh Tabataba’i in “Al-Mizan”. The first point reviewed is the idea of “Distinction between Facts and Credibilities”. According to the studies of the writer, this idea has impacted various fields of ma’arif ofRevelation such as: Monotheism, Resurrection, Man, etc. Instances such as: Divine ownership, legal Lordship, purposefulness of Divine Actions, reward and punishment, spiritual perfection and stations of human beings, creation of Iblis and infallibility, are among cases in which the impact of the idea of “Distinction between Facts and Credibilities” on them has been examined.