Whenever I stand beside one of those wonders of modern achievement, a great turbine engine, for example, smoothly and silently performing the work of a myriad men, I feel like taking off my hat to the geniuses (for the most part unnamed and unknown) who have made such a thing possible. There may be two opinions about the social effect of machinery, but there can be no two opinions about the prodigies of intelligence which have gone into its making. Everybody knows that machinery is scientific. And because of the vast esteem which our master mechanics rightly enjoy, the word Science has come to command a reverence once accorded only to the name of God. It is no longer possible to advertise a toy or a tooth-brush without calling it “scientific.” But what is Science? Is it a synonym for Truth? By no means. It is not even a search for truth. Truth is something general; the highest truth is universal. The search for it is called Philosophy. Science, as we now understand it, did not begin to have an independent existence until it definitely abandoned Truth as its province and devoted itself to the study of those--not general but particular phenomena known as facts. When we say that Science is classified knowledge we mean that it is our classified knowledge of facts. And in that word “classified” lies the root of its only difference from common sense. Science is also a method for ascertaining new facts as well as the classification of those we already know. What do we mean when we say that science is a method? What is its method? Every schoolboy can answer, “The method of science is the experimental method.” The experimental method itself is less generally understood. To experiment without an object in view is like starting on a journey with no destination in mind. In the vernacular phrase, it does not get you anywhere. The object of an experimenter is always to prove or to disprove something. And what is there for him to prove? A fact, once established, is already proven. But behind one fact there always lies another, and behind that yet others. We soon leave the world of certainty and find ourselves in the world of theories. It is a theory, then, which the experimentalist seeks to prove--his own theory, while disproving that of somebody else. Theories, dignified by the name hypotheses, are as necessary to science as are microscopes and scales. They are invented generalities used as conveniences in a region where Truths are too much to expect. A hypothesis does not even pretend to be true. It is merely the best approximation, the best guess, possible under the circumstances.