Question:

What did the scholar At-Tusi say about independent legal discovery (Ijtihad)?

Answer:

Abu Ja’far At-Tusi writes: “As for personal comparison (Qiyas) and effort (Ijtihad), both are not evidence (Dalil) with us, and the use of both is even forbidden.” [Uddat-ul-Usul, Volume 1, page 8]

قال شيخ الطائفة أبو جعفر الطوسي رحمه الله: وأما القياس والاجتهاد فعندنا انهما ليسا بدليلين، بل محظور استعمالهما