The business of the natural philosopher is to construct theories which will "save appearances" ....A scientific theory must 'save' or 'preserve' the appearances, the phenomena, it deals with, in the sense of getting them all in, doing justice to them....
But if we demanded no more than that from a theory, science would be impossible, for a lively inventive faculty could devise a good many different supposals which would equally save the phenomena. We have therefore to supplement the canon of saving the phenomena by another canon--first formulated with clarity by Occam. According to this second canon we must accept (provisionally) not any theory which saves the phenomena but that theory which does so with the fewest possible assumptions....
In every age it will be apparent to accurate thinkers that scientific theories, being arrived at in the way I have described, are never statements of fact....In our age I think it would be fair to say that the ease with which a scientific theory assumes the dignity and rigidity of fact varies inversely with the individual's scientific education...The mass media which have in our time created a popular scientism, a caricature of the true sciences, did not then exist. The ignorant were more aware of their ignorance then [in the Middle Ages] than now.

C.S. Lewis. THE DISCARDED IMAGE: AN INTRODUCTION TO MEDIEVAL AND RENAISSANCE LITERATURE.