"What is the Islamic position on stem cell research?" The question emerges innocuously in conferences held to discuss the new issues arising out of contemporary scientific research which require "religious" or "ethical" responses. Many Muslims participating in such conferences feel embarrassment, for not much can be said in response to such questions. This leads to action: a mufti is quickly sought to extract a fatwa so that embarrassing situations can be avoided in conferences where representatives of world religions discuss cutting-edge questions emerging from the latest advances in scientific research. Before the mufti can issue a fatwa, he, however, needs to know more about stem cells: What are they? Where are they located in the body? What they do? He is a distinguished fagih who has spent a lifetime acquiring knowledge of his discipline and is known internationally for his scholarly acumen, but he has no knowledge about the stem cells which are found in most multi-cellular organisms. This situation was, however, not unusual for Muslim scientists; they had previously been in similar situations with regard to organ transplants, test tube babies, embryo transplants, surrogate motherhood, and a host of other issues all of which had initially originated in the West and were then thrust upon other regions and religions of the world. On all these occasions, a mufti was sought and he was able to issue a fatwa that was later contradicted by another fatwa by an equally well-qualified mufti, whose later fatwa was then countered by yet another fatwa, the entire series giving rise to a host of mutually contradicting opinions and leaving the community of believers-the Ummah--in utter confusion. In this case, however, the situation was far more complex, both for the mufti as well as for those who had sought him out. Until the early 1960s, scientists believed that the brain does not experience any neurogenesis, that is, ongoing stem cell activity, after a certain age. When two Canadian scientists, Siminovitch L. McCulloch and J. E. Till, presented evidence for adult neurogenesis in 1963, the older scientific "belief" was relegated to history, and was now pejoratively called "dogma"--something flimsy, merely based on blind, unsound, untrue, and scientifically unprovable assumptions. This revision of a once firmly held "scientific belief"--Cajal's famous "no neuron theory"--did not occur overnight; in fact, the initial two papers by McCulloch and Till (published in Nature 197: 452-4 and Journal of Cellular and Comparative Physiology 62: 327-36) were largely ignored, and it was not until the early 1970s that a significant change took place in the attitude of the scientific community--a change that ushered a new era of scientific research.