The source that ideas, notions, principles and values are taken from, determines the nature of thought and its identity and properties along with its ability to grow, contribute, influence and be active. And, in as much as it is alive, rich and generous; the thought will be known as rich and both its structure and organic unity are cohesive. Also, Islamic thought is characterized as a thought that proceeds from rich and abundant sources which give it all the elements of strength, invention and continual growth. So, we can divide the sources of Islamic thought into two parts:

1. Primary Sources, including:

A. The Holy Qur'an

B. Sunnah of the Prophet

C. The Intellect/Reasoning

D. Consensus (i.e., of Muslim scholars on legal questions)

2. Secondary Sources, including:

A. Religious jurists' personal opinions

B. Opinions of observed Islamic thinkers