Comparative-Critical Review of the Views of Ibn Sina, Fakhr Razi, and Mulla Sadra about the Occurrence and Step of Nature

In this article, after the precise statement of the topic and purpose of occurrence and progress, Ibn Sina's, Fakhr Razi's, and Sadr al-Mutalahin Shirazi's views on the occurrence or time step of the natural world have been presented and critically analyzed. According to the historical order, Ibn Sina's opinion based on the antiquity of nature, and a reason for it, based on the natural-philosophical rule, "every event is preceded by matter and duration" is established. Then, the criticisms of Ghazali and Fakhr Razi, which are similar to each other, and Khwaja Tusi's response to Fakhr Razi's criticism are presented, and, in the continuation, the opinion of Mullasadra, which agrees with Ibn Sina, is narrated. In the following, a reference was made to Mulla Sadra's special opinion about the temporal occurrence of nature based on intrinsic movement, and it was pointed out that this opinion can be summed up with any occurrence or step of nature. Then, two side problems related to the discussion the infinite sequence of equipment and the specific problem of entities, have been raised and resolved. The summary and conclusion of the article are also given at the end and, in the conclusion, the theologian's opinion regarding the temporal occurrence of nature is ambiguous and inefficient, and the opinion of philosophers is preferred over nature's step.