After study, thought and investigation about the current situation of the Ummah and about what state it had reached, and the situation at the time of the Messenger of Allah (saw), and the time of the four Khulafa’a ar-Rashidun and the time of those who followed them, and referring to the seerah and the method by which he (saw) had carried the da’wah from the moment he had started until he had established the State in Madinah; and after studying the way that he (saw) functioned in Madinah and by referring to the Book of Allah (swt), and the Sunnah of His Messenger (saw) and to what they indicated of the Ijma’ of the Sahabah and Qiyas, and the enlightened opinions of the Sahabah and their followers, and the opinions of the mujtahideen, after all this Hizb ut-Tahrir then adopted thoughts, opinions and laws related to the idea and method. They are but Islamic thoughts, opinions and rules, nothing of which is un-Islamic, nor are they affected by anything un-Islamic; rather they are nothing but Islamic and they do not depend upon anything other than the sources of Islam. The Party resorts to thought in concluding these thoughts, opinions and rules.
The Hizb adopted the thoughts, rules and opinions that are necessary for it to proceed in the work to resume the Islamic way of life and to carry the Islamic da’wah to the world through the establishing of the Khilafah State and appointing the Khaleefah.
The Party enclosed all that it adopted and what was issued by it of thoughts, rules and opinions in its books and in its many leaflets which it published and issued to the people.
These are the books which the Party has issued:
The System of Islam
The Ruling System of Islam
The Economic System of Islam
The Social System of Islam
The Party Structure
The Concepts of Hizb ut-Tahrir
The Islamic State
The Islamic Personality (in three volumes)
Political Concepts of Hizb ut-Tahrir
Political Views of Hizb ut-Tahrir
Introduction to the Constitution
How the Khilafah was Destroyed
The Penal Code
The Rules of Evidences
Refutation of Marxist Communism
Presence of Mind
The Islamic Thought
The Refutation of the Theory of Liability in Western Law
A Warm Call
The Ideal Economic Policy
The Treasury in the Khilafah State
The Party has also issued thousands of leaflets, reminders and intellectual and political booklets.
When the Party carries these concepts and rules to the people, it carries them politically, i.e. it carries these concepts to them so that the people adopt them, act upon them and carry them to establish them in government and in life’s affairs. This is because it is a duty upon them as Muslims, as it is a duty on the Party as an Islamic party, and its members as Muslims.
The Party depends in its adoption of the Islamic thoughts and rules solely upon the revelation of the Qur’an, the Sunnah, Ijma’ of the Sahabah and Qiyas, because these four sources are the only sources whose proof has been confirmed by definite evidence.