This book was originally written by the great Muslim thinker and reformer Ayatullah Murtada Mutahhari on Mysticism for B.A. students at the faculty of theology of the University of Tehran. The original book was published after Mutahhari's martyrdom. A succinct yet deep exposition of the principles of Islamic theology is discussed such as a brief history of ʻilm al kalām and its various schools (Shiʻites, Muʻtazilites and Ashʻarites), the doctrines of tawhid, divine justice, retribution, free will and freedom, independence and validity of reason, the vision of God, the infallibility of the prophets and the Imams, intercession and more. The reader will get a concise picture of the foundational aspects of Islamic theology that can lead to further inquiry.