What is the nature of the scientific attitude, the attitude of the man or woman who studies and applies physics, chemistry, geology, engineering, medical or any other science? We all know that science plays an important role in the societies in which we live. Many people believe, however, that our progress depends on two different aspects of science. The first of these is the application of the machines and products that scientists and technologists develop. New drugs, faster and safer means of transport, new systems of applied knowledge are some examples of this aspect of science.