INTRODUCTION 



regarded as a final explanation. It is subjected to the most rigorous tests that 

 can be devised. If it stands these tests, it is more highly regarded as a 

 correct generalization, one which will render understandable all facts similar 

 to those upon which it is based and one by means of which predictions can be 

 made. Thus Mendel's generalizations about heredity have been confirmed in 

 a great variety of cresses and have, therefore, changed in status from hypotheses 

 to laws or principles of heredity. If we are acquainted with these principles, 

 we can predict what will happen when breeding experiments are performed. 



The method of science, then, uses the facts of nature as they can be verified 

 by all competent or trained observers. When these facts are recorded, they 

 are analyzed by logical processes of thought, and a generalization which cor- 

 relates the specific, separate facts is proposed. This generalization, or 

 hypothesis, is then tested and if found unsatisfactory is discarded. When 

 a hypothesis, or theory, has been refined until it seems to be entirely adequate 

 to explain a large body of facts and to serve as a basis for prediction, it be- 

 comes known as a principle or law. But no scientific principle is beyond 

 criticism; if new facts that cannot be correlated by its statement are dis- 

 covered, the principle must be revised or discarded. 



Science is a slave to the real state of things; truth is its taskmaster. And, 

 because scientists are human beings, they must be constantly on guard lest 

 prejudice or other emotional vices creep unrecognized into the path of rational 

 thinking. The material that is presented to you in this book has been gathered 

 by hundreds of men and women trained in the techniques of observation and 

 logical thinking. It is necessarily summarized without reference, in most 

 cases, to names or personalities, but it is hoped that your teachers will tell 

 you at times some of the fascinating human-interest stories about scientists 

 and their work. 



What can you as an individual in a democratic society gain by an under- 

 standing of the method of science? You will find that the method of science 

 leads to the accumulation of exact information which is subject to confirma- 

 tion by any competent observer. It will perhaps occur to you that this 

 accuracy of basic information is responsible for the steady progress of science 

 and the reliability of its applications. Propaganda, or attempted distortion 

 of facts, is no part of scientific procedure. What would be the result of the 

 application of the scientific method to the problems of social organization, 

 government, and international relations? What would happen if some of the 

 "diseases" of our social system were analyzed in an unprejudiced way by 

 competent specialists who were then permitted to conduct carefully planned 

 experiments in an eflTort to determine what treatment was most effective? We 

 live in an age of science, surrounded by the material benefits of sound observa- 

 tional and experimental practices. Will the time come when we extend these 

 sound practices in the obvious way and reap their benefits in a greater social 

 security? It will come when great numbers of you take an understanding of 

 the scientific method from your college classrooms and apply it to the prob- 

 lems which confront you as citizens in a democracy. 



