Shah Waliullah Muhaddith Dehlvi (February 21, 1703 – August 20, 1762) was an Islamic scholar and great reformer. His original name was Qutbuddin and later came to be known as Shah Waliullah for his pious habits. He was born during the reign of Mughal emperor Aurangzeb when spiritual conflicts, sectarian hostility, moral decline of society, social destruction, political distortion, poor understanding of the Holy Quran, and general ignorance of Islam were at peak.
Shah Waliullah despised the divisions and deviations within Islam. He explained the concept of Ijtihad in its true spirit. He worked hard for the regeneration of Islamic society in subcontinent.
Earlier theologians had recognized four schools of thought as being equally orthodox, they had conceded tacitly that there was room for differences of opinion in the interpretation of the sacred text. However, rigidity had crept into the thought of later scholars because they were afraid that the recognition of too many differences would breed anarchy of thought and encourage the rise of heresies. Thus Ijtehad should not go farther than the four walls of the recognized schools. This was the doctrine of “Ijtehad-i-Muqaiyyad” or limited scope of interpretation.
Amid this rigid thought, Shah Waliullah emphasized that the doors of Ijtehad had not been closed and pointed out that it needed both erudition and caution. He also laid down the principle that for those who were not qualified for Ijtehad it was incumbent to follow the rulings of competent Mujtahids.