Does Practice Validate Theory?
A theory, if true, can be employed successfully in applied research (technological investigation) and in practice itself-as long as the theory is relevant to either. (Fundamental theories are not so applicable because they deal with problems much too remote from practical problems. Just think of applying the quantum theory of scattering to car col- lisions.) But the converse is not true, that is, the practical success or failure of a scientific theory is no objective index of its truth value. In fact, a theory can be both successful and false; or, conversely, it can be a practical failure and nearly true. The efficiency of a false theory may be due to either of the following reasons. First, a theory may contain just a grain of truth, and this grain alone is employed in the theory’s applications. In fact, a theory is a system of hypotheses, and it is enough for a few of them to be true or nearly so in order to be able to entail adequate consequences if the false ingredients are not used in the de- duction or if they are practically innocuous. Thus, it is possible to manufacture excellent steel by combining magical exorcisms with the operations prescribed by the craft-as was done until the beginning of the nineteenth century. And it is possible to improve the condition of neurotics by means of shamanism, psychoanalysis, and other practices as long as effective means, such as suggestion, conditioning, tranquilizers, and above all time are combined with them.
