The Functions of Practical Reason in Shiite's Principles of Jurisprudence

The functions of practical reason are briefly and excursively discussed in the books discussing the principles of jurisprudence. Although many commands of practical reason are used in the principles of jurisprudence, both the major commands – such as the rule of rational badness and goodness - and the minor commands – such as the badness of Tajarri (daring against God), the badness of wasting God's purposes, and the goodness of precaution, but this subject is not separately and elaborately discussed in any one of these books. Some aspects of this subject are discussed in some precedent books; for example the discussion of goodness and badness is discussed in these books: 'Al-Favaed Al-Haeriyyah' (refer to Vahid Behbahani, 1415 LAH, pp. 363-378), 'Al-Fosoul Al-Qaraviyyah' (refer to Saheb Fosool, 1404 LAH, pp. 316-350), 'Faraed Al-Osool' (refer to Sheikh Ansari, pp. 230-245) and 'Hedayah Al-Mostarshedin' (refer to Mohaqqeq Isfahani, pp. 433-442). But in the books of recent scholars this little discussion is also rarely found; it is only Isfahani (Mohaqqeq Isfahani, 1374 SAH, v. 2, p. 322 on) who has mentioned this discussion while he presents the reasons of Insidad (lack of religious sources). Martyr Sadr has also mentioned this discussion in his different books to some extent; and recently one of his pupils, Abu Raqif, has presented an independent discussion regarding the applications of practical reason in the principles of jurisprudence in a two volumed book named 'Al-Osas Al-Aqliah'. It is clear that these discussions should not be discussed in the principles of jurisprudence rather they should be discussed in the philosophy of the principles of jurisprudence; and this science, like the philosophy of other sciences, has not been completely developed in religious fields. Yet some worthy scholars have made great efforts in this regard and have tried to establish these sciences.* After explaining the meaning of expressions of this subject and the meaning of practical reason and clarifying the subject and its range, the functions of practical reason in the principles of jurisprudence will be explained in this article.