Uṣūl al-Dīn (Arabic: أصول الدین) or principles of religion or roots of faith are a set of essential beliefs in Islam that every Muslim needs to believe in; otherwise, he would not be considered a Muslim. tawhid [oneness of God], nubuwwat [prophethood of the Prophet Muhammad (s)], and resurrection are the three main principles of Islam. All of Islamic sects believe in these three principles; but each one have special principles which separates it from other sects.
For the Shi'a, 'adl [justice of God] and imamate are the additional principles needed to be accepted. However, the two principles of justice and imamate can be considered separate from the other three.
Knowing the principles of religion is obligatory; but there is disagreement whether certainty of the principles is required or supposition is enough. Also there is discussion over the sufficiency of believing in the principles of religion out of emulation (taqlid).
Most religious scholars believe that emulation is not permissible in usul al-din and everyone needs to think about these principles for himself and accept them with certainty.
Meaning of Usul al-Din
Usul al-Din refers to two different senses. The first sense commonly includes all Islamic theological principles opposite to minor issues in religion. In this sense, the Usul al-Din are theological principles which are to be thought about, and Furu' al-Din are the issues which are to be observed, whether followed or abandoned.
Its other application refers to the three or five theological principles of Tawhid (oneness of God), Nubuwwat (prophethood), 'Adl (justice of God), imamate and resurrection. However, often the three principles of Tawhid , prophethood, and resurrection are called Principles of Religion and the two concepts of justice and imamate are called Principles of School (School of Twelver Shi'a); yet at times they are all grouped together as the principles of religion.
Cause of Naming
Those who have made this title have called these beliefs as Usul al-Din [Principles of Religion] because they believe all Islamic sciences such as hadith studies, fiqh and tafsir are interdependent on these principles. In other words, Islamic sciences rely on accepting the Prophet (s) and accepting him depends on knowing these principles.
Moreover, it can be noted that these principles are defined so that the distrinction between Islam and other religions as well as the distinction between Shi'a and other sects are preserved; such as, accepting imamate, separates the Shi'a from Sunnis and with justice, Shi'a are separated from Ash'arites.
Sometimes Usul al-Din has been used to address a more specific concept. For example, it has been used to refer to the science of Kalam (Islamic theology).
Usul al-Din in the Qur'an and Tradition
However, there are hadiths that mention principles in Islam. For example, a hadith narrates Imam al-Sadiq (a) was asked, "What are principles? And what are the issues everyone needs to have knowledge about, should not be ignorant about, otherwise whose beliefs would be spoiled and God would not accept his deeds and if anyone knows them and acts upon them, his religion would be corrected and his deeds would be accepted?" Imam answered, "Declaring belief in oneness of God, prophethood of the Prophet (s), acknowledging what is revealed from God, paying Zakat and acknowledging Wilaya of the Progeny of Muhammad (s), among whom Wilaya is of special importance."
In another hadith, Imam al-Baqir (a) said, "Islam has five pillars of daily prayers, Zakat, Fasting, Hajj and Wilaya which is most important of all." Such hadiths show that some Islamic beliefs are so valuable that rejecting them implies a rejection of Islam, while the acceptance of other pillars do not result in the same implication.
Deep Religious Conviction or Mere Conjecture
There is no disagreement over the necessity of believing in Usul al-Din, but there are different opinions about whether believing in Usul al-Din needs to be based on assured knowledge or if conjectural knowledge is enough. There are also debates regarding acquiring conjectural knowledge, specifically if it needs to be obtained through reasoning or if emulation is enough. Most scholars say that believing in Usul al-Din needs to be based on assured knowledge and the faith upon conjecture is not enough.
Their theory is defended with verses of the Qur'an and hadiths that criticize acceptance through assumptions such as "indeed conjecture is no substitute for the truth," (Q,10:36); "They follow nothing but conjectures and they do nothing but surmise," (Q,6:116); "And they only make conjectures," (Q,45:24).
Contrary to the former opinion, some other scholars have considered a strong supposition for believing in Usul al-Din enough and have said that a strong conjecture makes the heart tranquil, and that in the view of religion, a true knowledge is not beneficial if not resulted in tranquility of the heart. Therefore, what is necessary with regards to believing in Usul al-Din is receiving certainty at the heart which is commonly called certitude. In certitude, there is no absolute protection from mistake; however, it is disregarded since it is weak, contrary to logical certitude, in which there is no possibility of conjecture.
Emulation or Studying in Usul al-Din
Most Muslim theologians believe that emulation in Usul al-din is not permissible and knowing them needs to be acquired through studying. There has been general consensus on this issue as well.
One of the reasons for this being impermissible is that the emulator either knows the truthfulness of the authority he is following or not: if he does not know, then he can estimate the error in the authority, and thus his emulation is not wise, since he is following what is not immune from error. However, if he knows that the authority he is following is on the right path, then he has either made this conclusion in three conditions: either out of transparency which is null and void, out of emulation which the number of people emulating whom is necessary, or through studying which is the only rational assumption in which the person may have concluded the truthfulness of the authority. This is actually not emulation and thus emulation in Usul al-din is invalid.
Usul al-din from the Viewpoint of Twelver Shi'a (Imamiyya)
The most popular opinion is that Usul al-din includes three concepts: Tawhid (oneness of God), Nubuwwat (prophethood), and resurrection, to which 'Adl (justice) and imamate are added as the Principles of the School. In other words, if someone rejects one of the three Usul al-din, he is considered a Kafir [unbeliever], but if he accepts the three fundamental principles but rejects either justice [of God] or imamate, then he is a believer, but he would not be a Shi'a.
According to the common opinion of Twelver Shi'a scholars, the five mentioned principles are defined as following:
1- Tawhid (Oneness of God):
- Main article: TawhidKnowing God and acknowledging the fact that from pre-existence to post-eternity, He exists and is Necessary Existent. The concept of Tawhid acknowledges positive attributes for God such as infinite power, knowledge, and existence as well as rejecting negative attributes from Him such as ignorance, inability to do anything, or imperfection. This also implies believing in the fact that God's attributes are the same as His essence, and that He has no additional attributes to His essence.
2- Justice [of God]:
- Main article: 'AdlKnowing that God is Just and Wise. This means that He does not do any wrong and does not abandon any proper act. God is not content with the wrong humans do. Therefore, humans hold the absolute responsibility for their actions, whether good or bad.
- Main article: NubuwwatAcknowledging the prophethood of the Prophet [[Muhammad (s)] and what has been revealed to him. However, there is a disagreement on whether this principle applies solely to generally acknowledging what the Prophet (s) has said as revelation or if one needs to acknowledge the revelation in details. Some Twelver Shi'a scholars also deem it necessary for one to believe that the Prophet (s) was infallible, and he (s) was the last prophet.
- Main article: ImamateAcknowledging imamate of the twelve imams (a). All Twelver Shi'a theologians agree on this as it has been considered one of the two required principles of Shi'a. All imams are infallible and guardians of religion. They are responsible for guiding humans toward the truth and everyone needs to obey them. This concept also includes accepting that The Twelfth Imam (a) is alive and in hiding, but one day he (a) will reappear with the permission of God.
- Main article: ResurrectionThis principle implies that humans will be resurrected one day in front of God, and their good and bad actions will be judged. All Muslims believe in physical resurrection which suggests that the body to which humans will be resurrected is physical.
- The material for this article is mainly taken from اصول دین in Farsi Wikishia.