Microcosm and Macrocosm

Medieval theories of the microcosm developed separately in the three religious traditions, but there were some points of contact between Jews and Muslims. The Talmud and the Midrash included a few microcosmic references, and the theory was very prominent in the mystical tradition known as the Kabbalah. The earliest kabbalistic text, the Book of Creation (Sefer Yezirah; perhaps composed between the third and sixth centuries C.E.), observed correspondences between the letters of the Hebrew alphabet, features of the physical world, and the human body. The thirteenth-century Book of Splendor (Zohar) taught that the first emanation in the creative process is the cosmic man (Adam Kadmon), through whom the rest of creation emanates, so that terrestrial human beings are modeled on an ideal form that provides the pattern for all of creation.

Arabic influence may have inspired two Jewish philosophers, Ibn Gabirol (Avicebron, c. 1021–c. 1058) in his Fountain of Life, and Ibn Saddiq (1075–1149) in his Microcosm, to combine microcosmic speculation with the Delphic maxim, "Know thyself"; both demonstrated how self-knowledge leads to knowledge about the universe. Although Maimonides (1135–1204) found fault with certain aspects of microcosmic theory in his Guide for the Perplexed (1.72), he nevertheless accepted much of it.

The most remarkable development of the microcosm among the Muslims appeared in the encyclopedia known as the Epistles (Rasa'il) of the Brethren of Purity (Ikhwan-al-Safa) in the city of Basra during the tenth and eleventh centuries. While two of its fifty-two treatises are devoted to microcosm and macrocosm, correspondences between the two worlds are noted throughout the work as it traces the procession of creatures from God and their mystical return to God through human understanding. Al-Biruni (973–c. 1051) accepted the microcosmic model, while Ibn Sina (Avicenna, 980–1037) made it the foundation of his theory of medicine.