Abstract

The terms theory, fact, and hypothesis are sometimes treated as though they had clear meanings and clear relations with one another, but their histories and uses are more complex and diverse than might be expected. The usual sense of these words places them in a relationship of increasing uncertainty. A fact is usually thought of as a described state of affairs in which the descriptions are true or highly supported. A highly corroborated or supported hypothesis is also a fact; a less well corroborated one is still a hypothesis. A hypothesis which is not supported by or corroborated by other evidence would not be a fact, but could become a fact if it came to be corroborated to a high degree of certainty by other evidence. Similarly, a theory, which is a logically connected set of hypotheses, could come to be a fact if the hypotheses in the theory were to be highly corroborated by the evidence.