The magnitude of the worlds problems has encouraged doubt and pessimism among some of its most creative thinkers. Yet the majority of those charged with the responsibility of finding solutions to the problems. Primarily politicians and civil servants. Remain cautiously optimistic. For solutions they have continued to turn, paradoxically, to those agencies responsible, in many cases, for the creation of the problems: science and technology. Scientists and technicians invented and perfected the internal combustion engine and the chemical DDT. Now other scientists and technicians are seeking ways to combat their deleterious effects. Scientific research has been responsible for the medical advances which have helped to produce worldwide population increases. No one would argue, of course, that the research should not have taken place, or that the continuing battle against disease is not one of humanitys most worthwhile engagements. Most would agree, however, that science must move as quickly as possible to come up with a safe and simple method of birth control as it continues to fight to prolong life. The achievements of science in the field of health during the past half- century have been truly remarkable. One discovery in particular has enabled scientists to understand more clearly the ways in which the human body receives and transmits disease. The discovery of viruses was the result of experimentation conducted chiefly by the American biochemist Wendell Stanley in the 1930s. Viruses are microscopic organisms which show show signs of life-including the ability to reproduce only when existing inside living sells They are the cease of many human diseases, including measles, poliomyelitis (infantile paralysis) , and rabies, Not until the nature of viruses was understood cloud scientists begin to develop means of treating and preventing the virus produced illnesses in human beings.