The ideology of Islam consists of two key aspects: a set of beliefs i.e. the creed, and a system of rules regulating man's actions emanating from the creed. And Quran is the primary source for both of them.

Quran is definite i.e. nothing has been added or deleted from it since it was revealed but this does not necessarily means that the meaning of the text is definite. If there is only one possible understanding of the text then the meaning is considered definite and the sharaih (corpus juries of Islam) derived from the text is an assured rule. On the other hand, if the meaning of the text is open to more than one interpretation, the rule is derived from the text through Ijtihad - the process of making judgment based on Quran, Sunnah i.e. actions of the Prophet and his words of commandment, and qiyas i.e. divine analogy.

Examples of the use of Ijtihad amongst the sahabah - companions of the Prophet (saw), are numerous. Following are some of the examples:

1. Quran says: "As for the thief, both male and female, cut off their hands", but during the year of famine - which resembled the case of plight, Caliph Umar suspended the penalty for theft in view of the verse "Whosoever is forced to transgress the laws without violating the laws, then there is no sin against him"

2. During the opening of Syria and Iraq, the sahabah disagreed over what should be done with the land they had opened. Some considered that the land should be divided into fifths as Quran prescribed. They were of the opinion that the four fifths of the land should be divided among the soldiers and the remaining one fifth should be distributed to those whom Allah has commanded in the Quran "Then truly to Allah belongs one fifth and to the Messenger, the Messenger's family, the orphans, the poor and needy and the wayfarer". Eventually, it was decided that the land should remain in the hands of the owners but under the authority of the Baytul Mal (treasury for the purpose of providing social security benefits) where every Muslim, including those identified in the verse, could benefit from it.

3. Another example concerns the time of waiting (iddah - the period after which a woman can marry - a safeguard for ascertaining the correct fatherhood of a child) for the pregnant wife who becomes widowed. In view of the verse "For those who carry life in their wombs, their period is until they deliver their burden", there was an opinion that when a man dies and leaves a pregnant wife, her time of waiting expires at the birth of the child. While in view of the verse "If any of you die and leave widows behind, they shall wait concerning themselves four months and ten days" there was another opinion that the time of waiting expires either when she gives birth or after 4 months 10 days, whichever is the longest duration. In other words, if the woman gives birth 8 weeks after her husband's death, she still has to wait the remaining 2 months and 10 days. It was resolved that each of the verses was interdependent and, were connected ingeneral to the other. The second verse in linked to the first which gives the understanding that the women whose husband has died, is under iddah for four months and ten days if she is free from pregnancy. However if she is pregnant, her iddah expires when she has given birth.

Ijtihad has been a long established Islamic practice to find answers to new situations and differing circumstances. Sahabah were fortunate to be trained in Ijtihad by Prophet (saw) and by the events of that time. But after that it became more and more crucial and most practical to consider not only Quran and sunnah in Ijtihad but also their derivatives i.e. Ijma -as- sahaba (consensus of companions) and qiyas through hadiths, Islamic history and sharaih.

Muslims have had different opinions since the time of the Messenger of Allah but it should not be seen as a weakness and source of disunity. The weakness and disunity is not the difference of opinions but rather in the way in which such differences are viewed. As long as an opinion is based on an Islamic evidence, and that opinion does not contradict an assured rule, that opinion should be respected as an Islamic opinion.