Al-Ghazali underwent several intellectual stages in his evolution as a scholar. He began his studies in jurisprudence and the Quran before embarking on a 3-year study of Sufism. He then studied further subjects including theology, logic, and natural sciences. In his quest for certain knowledge, he abandoned strict adherence to past teachings and doubted conventional means of knowledge. He explored different fields including theology, philosophy, and mysticism before finding satisfaction in the teachings of mysticism and ethics.