This study starts by observing the duplicity that exists in the legal culture in the Arab and Islamic world, stemming, as it does, from the interaction with western legal culture, while a t the same time preserving the Islamic legal culture . This study aims at opening the way to unify the two cultures, in such a manner that would serve pedagogic and educational purposes in a contemporary Islamic society. The projected study consists of consecutive essays, and begins with this essay which discusses the issue of the definition of law. This essay comprises four points: The first point criticizes the common accepted definition of law as: "a set of rules of behavior which the public authority gran tees their enforcement and people's respect and compliance with them" The criticism maintains that this definition does not achieve the function which a successful definition is expected to achieve, namely to draw a clear portrait of the definindum in our minds, in such a manner that it becomes totally distinguishable from similar concepts. Such a successful definition can only be achieved by giving the nearest genus and difference. The second point attempts to find and discover the nearest genus of law in the conception of: "Khitab al-Shari' al-Muta'aliq bial-al-mukallafin "Which is given in Islamic Jurisprudence as a definition of al-Hukm (Law) by the Muslim Jurists (aloosuliyin). An attempt will be made to see how far is this conception of "Khitab al-Shari'a is consistent both with the Islamic and the contemporary western definitions of law. The third point attempts to discover the nearest difference of law through the investigation of the close link between religion and morality. Then the differences between law and morality are being investigated and the conclusion is consequently reached that while the objective of law is the setting-up of social structure of system, the objective of morality is to inculcate moral virtues. Thus law and morality could have a common ground, and could agree on a common set of rules and regulations. But they could also diverge. In the fouth point, a criticism is given of the distinction between prescriptive and the interpretational or complimentary legal rules as regards its general logic and also as regards some of its practical conseq uences. It is them explained that distinction is not really a distinction between two different t kinds of legal rules sterling from "Khitab al-Shari", but they are actually two divisions of this Khitab of al-Shari 'a (law) itself and thus it does not touch the essence of the rules being generated from it.