Signs. The natural sciences of botany, geology, and zoology have held a central position in the Muslims' world-view, which sees all objects in nature as signs of God's mercy and majesty. The Qur'an encourages Muslims to reflect on the inner, religious meaning of nature and to live in harmony with the natural world: "By the sun and its glorious splendor; By the moon, as it follows the sun; By the day as it shows up the sun's glory; By the night as it conceals it; By the earth and its wide expanse; Truly he succeeds that purifies it, and he fails that corrupts it" (91: 1-10). Early Muslim manuscripts on natural history covered vast numbers of subjects. Some gave detailed descriptions of natural phenomena, while others took a symbolic and mythological outlook, but they all viewed nature as a source of wisdom beyond the...