The Age of Enlightenment brought about impressive achievements in scientific understanding that pertained to medicine. Documentation of the anatomy progressed rapidly, and there was greater understanding of how certain bodily systems worked. Scientists expressed great hope for the future with some proclaiming that because scientific knowledge was growing so rapidly, disease would soon be completely eradicated. Yet the actual cause of illness still stymied them. Though microscopes provided the capability of seeing "little animalcules," no one had drawn a line between the presence of what we...

Scientists did not know what made people sick more than 150 years ago. There were many theories of how and why illness spread, but none of them were accurate. Though very primitive microscopes had permitted the examination of bacteria as early as the 1660s, it was not until the mid-19th century that bacteria's contribution to the spread of illness was understood. It was during this time that surgeons routinely examined patients in the morning and then performed surgeries in the afternoon--without wearing gloves or washing their hands first. Physician Ignaz Semmelweis made the connection...

Many people take for granted that physicians know what they are doing, but every day scientists must make very difficult decisions. Just because scientists can harvest stem cells, doesn't mean that they should; and while one day nanotechnology might mean a little "nanobot" can be turned into a blood vessel to clean out the arteries, there are some ethical and environmental issues that must be considered first. Today people can be kept alive mechanically, but physicians must wrestle with how long breathing on a machine should continue before a person is declared dead and their organs can be...