Studying the nature of canonical decrees has been a subject of the Principles of Jurisprudence for a long time. Historically, the study of the nature of a decree in Shia Principles of Jurisprudence was discussed by Allameh Helli in his book, Tazhib al-Wusul Ila Ilam al-Usul. There is no unanimity among the Shia jurisprudents about the study of the nature of canonical decrees. Some of them consider a decree the address of Sharia which belongs to the deeds of the faithful based on requirement, situation or will. Some others consider decree a legislative determination which is revealed through addressing. Some others consider canonical decree like a general proposition coined for subjects whose existence is supposedly accepted as true theorems. While criticizing the principles of the said theories, Imam Khomeini considers canonical decree conventional ideas  whose place are in the conventional world; therefore, the viewpoints of the jurisprudents in the field of studying the nature of canonical decree include address, legislative will,  coining and conventional ideas.