This is a woman's firsthand account of a Sufi <i>halvet, </i>a forty-day retreat conducted in complete isolation, along with strict fasting from sunrise to sundown. Voluntarily confined to a sparsely furnished room amid the bustle of Istanbul, Michaela Özelsel will occupy her time with reading the Qur'an and works of Rumi and Ibn 'Arabi, and with praying and practicing the powerful Sufi exercise known as <i>zhikr,</i> the rhythmic repetition of names of God or other sacred formulas, accompanied by movements of the head or body. <br><br>In intimate detail Dr. Özelsel shares her experiences as she strives to attain true "Islam" in its meaning of surrender or unconditional acceptance of the will of God. Her daily journal ranges over the frustrations of noisy neighbors, power outages, and a poorly heated room; her inner longings, doubts, and memories of the life course that has brought her to this moment; and the most inspirational philosophical insights, dreams and visions, and ecstatic raptures. <br><br>The second half of the book is devoted to the author's psychological and cultural commentary on her experiences, including observations about the methods of Sufi schooling, sexuality and spirituality, and the relationship with the spiritual guide. <i>Forty Days </i> is unique in the literature of spiritual education because it is informed by her knowledge of contemporary research from several disciplines, thus creating a bridge between ancient wisdom and scientific investigation.