His full name is Qu峁璪 ad-Din A岣ad Wali Allah ibn 'Abd ar-Ra岣m al-鈥楿mari ad-Dihlawi. His father is Shah Abdur Rahim, Islamic scholar himself whom had been compiled Fatawa-e-Alamgiri, a compilation of Hanafi lexicon and founder of the Madarssa-i-Rahimiya. In this school, Shah Waliullah received his early education until at the age of 15, he mastered all major branches in Islamic studies. At the age of 17, Shah Waliullah succeeded his father as the Shiekh of madarssa, For twenty years, Shah Waliullah had been teaching at that school until 1724, when performed the Hajj and studied under the great religious scholar, Shiekh Abu Tahir bin Ibrahim in Madinah for 14 years.
This is an excellent resource for scholars and students of knowledge on the importance of Ijtihad, the dangers of ulema making Taqleed, and the wisdom and benefits behind the different laws of Islam.
However, the book is written in quite a scholarly manner and so I wouldn't recommend it to someone who hasn't studied the Usool Al-Fiqh or Maqasid Ash-Shariah.
It's little different from classical islamic texts that, in his treatise Shah Waliullah tries to explain the very underlying logical justification of almost all of the islamic laws, he also ventured greatly on the spiritual aspect of islamic life. In a nutshell Shah Waliullah tried present a very logical picture of Islam, and he definitely succeeded.