IN THE EARLY 17TH CENTURY, SIR FRANCIS BACON SET OUT ON A QUEST to unravel the secrets of the natural world. His approach was singularly encyclopedic, involving careful scrutiny of every imaginable phenomenon from the currents of streams and the recesses of caves to the decay of bodies, the condensation of rain, and the refraction of light. What was his ultimate purpose? Nothing less, he expounded in The New Atlantis, than "the knowledge of causes, and secret motions of things; and the enlarging of the bounds of human empire, to the effecting of all things possible." 1 Interestingly, Bacon's pursuit has parallels in our own era. The Human Genome Project, with its encyclopedic approach to gene identification, is reminiscent of the scope of Bacon's early explorations. While Bacon's lofty goals seem remarkably grandiose, it is not entirely clear that our ambitions today are more modest. For example, James Watson, as head of the Human Genome Project, ventured that the characterization of the human genome would eventually provide us with "the ultimate answers to the chemical underpinnings of human existence." 2 One of the most conspicuous differences between Bacon's time and ours is the advent of modern technology. The research tools now available to scientists and clinicians offer unprecedented magnifying power for the study of biological processes. As a result, medicine has progressed from gross anatomical descriptions of disease to precise characterization of physiologic and pathologic phenomena at microscopic and molecular levels. As the editors of the New England Journal of Medicine recently concluded, "It is hard not to be moved by the astounding course of medical history over the past thousand years. No one alive in the year 1000 could possibly have imagined what was in store." 3 This month, MS JAMA examines several emerging technologies that are assuming increasing importance in the practice of clinical medicine. George Scarlatis comments on recent advances in the use of retinal and cortical stimulation to restore vision. Max Diehn, Ash Alizadeh, and Patrick Brown examine how complementary DNA microarray technology is redefining molecular medicine. In the closing article, Steve S. W. Han and Itzhak Fischer review advances in stem cell research and describe preliminary results on the repair of traumatic spinal cord injury in an animal model. See the MS JAMA Web site for Field Willingham's discussion of the technological innovations transforming medical education at the University of Maryland. Medical students and physicians have access to a rapidly growing armamentarium of medical technologies. With these expanded capabilities comes a responsibility to introduce new innovations with discretion. Medical advances will never achieve their full potential unless they are well understood, thoughtfully applied, and critically evaluated. Only by staying abreast of new advances can medical students and physicians rise to the challenges and opportunities afforded by emerging health care advances.