Apostasy in Islam (Arabic: ارتداد, irtidād or ridda‎) is commonly defined as the rejection in word or deed of their former religion (apostasy) by a person who was previously a follower of Islam. The four major Sunni Madh'hab (schools of Islamic jurisprudence) all agree that apostasy is a sin as long as the individual does not do so in ignorance or under duress. They also differentiate between harmful apostasy and harmless apostasy (also known as major and minor apostasy). According to Wael Hallaq nothing of the apostasy law are derived from the Qur'an, although the jurist al-Shafi'i interpreted the Qu'ranic verse 2:217 as providing the main evidence for apostasy being a capital crime in Islam.