The Criteria for Theory Selection

A theory should be consistent, not only internally or with itself, but also with other currently accepted theories applicable to related aspects of nature. A theory's consequences should extend far beyond the particular observations, laws or sub theories it was initially designed to explain. Fourth, and closely elated, it should be simple, bringing order to phenomena that, in its absence would be individually isolated and confused. Fifth, a somewhat less standard item, but one of special importance to actual scientific decisions, a theory should be fruitful of new research findings. These five characteristics, accuracy, consistency, scope, simplicity and fruitfulness, are all standard criteria for evaluating the adequacy of a theory.