Men have distinguished themselves from other animals, and in doing so secured their survival by the ability to observe and understand their environment and then either to adapt to that environment or to control and adapt it to their own needs. The process of careful observation, perception of a pattern in the phenomena observed, followed by use of this knowledge, has largely inspired the area of human activity known as 'science'. It has also provided the basis for the traditional methodology of science. It includes objective observation, description of some phenomena, the statements of hypotheses(假说) about the events observed and possible relationships among them, the use of these to predict future events, the evidence of the hypotheses and the construction of a theory based on the evidence of the hypotheses. But the classic 'scientific method' has been criticized from a variety of points. To begin with, it is obvious that the 'objectivity' of science strictly characterizes only the lowest order of scientific activity—observation. Even here it is doubtful whether anyone can be a truly impartial observer of events. What someone chooses to observe and the way one observes it must, after all. in part be a reflection of experience and of ideas as to what is important. Consider, for example, the different ways in which an artist and a layman look at a painting and the different reactions they have to the same work. The construction of hypotheses and theories reflects the scientist's interpretation of what he or she has observed even more clearly than observation. At this stage of the scientific method, an element of subjectivity is inevitably present. This can most easily be seen in the extreme case of scientists of truly creative genius. Galileo, for example, challenged the scientists of his day with his hypothesis that the earth revolved around the sun. A twentieth century example is Watson and Crick's discovery of the molecular structure of DNA. Obviously, science may involve not only careful observation but also a willingness to be creative. Human beings differ from animals because they can ______.