Although ‘definition theories’ are parts of Logic, we have seen its application to many Islamic disciplines such as F ıqh, Usul al-Fiqh, Theology, etc. But the questions as to whether it suffered any amendments on the one hand, and whether the Theologians added new elements to this theory still await to be answered. So in this paper this theory will be dealt with first, and then Theologians’ contribution will be tackled.