The Impact Of The Difference In The Consideration Of The Purposes Of The Differences Mujtahids PHD (Doctor of Philosophy) thesis by researcher: Muhammad Mustafa Muhammad al-Astal. This thesis was supervised by Professor Dr. Abdul Karim Zidan, and it was discussed in Republic of Yemen/ Sana’a University/ College of Arts/ Department of Islamic Studies in the year 1427AH / 2007 AD to obtain a PHD degree in The Islamic jurisprudence.