The lecturer tries to explain the most important sciences, knowledge, skills and experiences needed by the researcher in studying the principles of jurisprudence of financial transactions, from a legitimate scientific dimension and a fundamentalist jurisprudential vision in a general presentation. Through the texts of the imams, and through: the legitimate interests and scientific considerations, in the light of guidance in mind, and rooting the face of its choice, and to submit to others, and has to verify the antagonist to lower the jurisprudence of transactions. This, in the statement and rooting, illustrates the complexity of this presentation: with critical views and reflections on some of the imbalances and imbalances that appear to the lecturer in studying this dangerous scientific dimension in this difficult time.