Maslahah is considered to be the last theory in the development of Islamic jurisprudence. Literally, maslahah is an infinitive noun of the root salaha. It has different implication depending on the variety of context in which it is used. Saluha its verb form is used to indicate being good, right, virtuous, honest or to show the state of possessing these virtues. Its use in relational sense denotes a cause, a means, an occasion or a goal which is good or is for good (Lane ' n.d.). When used as a noun it mean something considered good or useful (Rida' n.d.). Madarah (harm) and mafsadah (evil) are its antonyms. In general sense maslahah means welfare (Bosworth 1978). Technically, it means the consideration of the purposes of the law and the means of their realization. Its signification in this sense is clear from Imam al-Ghazali's statement: what we mean by maslahah is protection of the purposes of Shariah which are: preservation of religion, life, reason, descendants and property (al-Ghazali 1949). It also includes the means which lead to preservation of these five principles. Hence, maslahah in its essence is not only securing of benefits and prevention of harm, but it also needs to be in harmony with the objectives of the law-giver. Thus, as a method of interpretation of law it plays a crucial role in providing the ruling for new issues for which there exists no explicit evidence in the texts. It is therefore, a comprehensive method in its nature, for it extends the law to all areas of human activities. This underlying line of thought in the conception of maslahah renders it as a potential instrument for the revitalization Islamic thought. Therefore, this article attempts to analyse its role as a dynamic principle of the methodology of usul al-fiqh (the principle of Islamic jurisprudent) and as an instrument for revival of ijtihad. However, prior to this a brief sketch of the development of the usul al-fiqh is presented in the following.Historical SketchUsul al-fiqh, according to the generally accepted view in traditional Islamic law, governs the judicial process and determines beforehand the methodology that is to be employed by the jurists for the discovery of the law and its application to a given set of facts. In fact, it provides a criterion for a correct understanding and evaluation, for almost every discipline of Islamic knowledge (Kamali 1999). In other words, usul al-fiqh lays down a methodology for jurists to be followed. For this reason it is indispensable for Muslim jurists to have a thorough grounding in Usul. The understanding of a detailed legal theory with its predetermined methodology had not been a prerequisite for the practice of the Islamic law prior to al-Shafii, hence no legal theory had been systematically recorded till the last decade of the second century. However, the law during this period grew from the inner essential core into a highly consistent and mature system (Nyazee 1994). Even though nothing of the discipline now known as usul al-fiqh had emerged with its particular terminology, it does not mean that jurists did not adopt a methodology for the discovery of the law. It only means that no legal theory was expounded so as to understand and analyse this methodology. Nonetheless the various ijtihad processes employed during this period could be classified under the various forms of the principle of maslahah. Thus, the lack of an elaborate legal theory should not be taken to mean absence of a sound methodology. This is because the derivation of detailed rulings on particular issues from the sources of law was a matter of instinct, to the first generation of Muslims, just as they spoke Arabic instinctively. Therefore, there was no need for recording the methodology they used for deriving rulings.Usul al-fiqh as a guideline for mujtahid in various ways of using source materials, was not used until Imam al-Shafii put it to use in his new fiqh (al-Shafii 1338H). From then onward skill in legal theory had to be a prerequisite for jurists. …