The research addresses a fundamental Islamic jurisprudential Purposeful issue, which is (Sharia), and to indicate the impact of this on Islamic jurisprudence, deriving rulings and extracting purposes, and to repel the illusion that this issue is only doctrinal, and clarifying the aspects of similarities and links between them by explaining the origin of deriving the purposes of Islamic Law (Sharia) through the meanings and wisdom learned from the texts and the explanation of the rulings. The rulings of Islamic Law (Sharia) have urged bringing benefits and repelling harms, and that the path to do so is reason and its production. I began the research by defining the purposes of Islamic Law (Sharia), then defining the rule of rational rightness and wrongness, then explaining the relationship between the two definitions. Thereafter, I presented the opinions of the Islamic jurists on the issue of rational rightness and wrongness and the weight opinion between them, and clarified some examples of the applied Islamic jurisprudence issues. Then I spoke about the derivation of the purposes of Islamic Law (Sharia) and its relationship to the rule of rational rightness and wrongness, and explaining the common origin between the purposes of Islamic Law (Sharia) and its relationship to the rule of rational rightness and wrongness and its impact on Islamic jurisprudence. Then I spoke about the truth of the relationship of the rule of rational rightness and wrongness to the purposes of Islamic Law (Sharia), and the relationship of that to the concept of appropriateness and its impact on the relationship between them