Scientific Method

Scientific thought aims to make correct predictions about events in nature. Although the predictive nature of scientific thought may not at first always be apparent, a little reflection usually reveals the predictive nature of any scientific activity. Just as the engineer who designs a bridge ensures that it will withstand the forces of nature, so the scientist considers the ability of any new scientific model to hold up under scientific scrutiny as new scientific data become available.

It is often said that the scientist attempts to understand nature. But ultimately, understanding something means being able to predict its behavior. Scientists therefore usually agree that events are not understandable unless they are predictable. Although the word science describes many activities, the notion of prediction or predictability is always implied when the word science is used.

Until the seventeenth century, scientific prediction simply amounted to observing the changing events of the world, noting any irregularities, and making predictions based upon those regularities. The Irish philosopher and bishop George Berkeley (1685-1753) was the first to rethink this notion of predictability.

Berkeley noted that each person experiences directly only the signals of his or her five senses. An individual can infer that a natural world exists as the source of his sensations, but he or she can never know the natural world directly. One can only know it through one's senses. In everyday life people tend to forget that their knowledge of the external world comes to them through their five senses.

The physicists of the nineteenth century described the atom as though they could see it directly. Their descriptions changed constantly as new data arrived, and these physicists had to remind themselves that they were only working with a mental picture built with fragmentary information.