 One can express Bacon’s position as follows: experimentum is the universal source for our discovery of scientific principles. Scientific knowledge, once established, proceeds by demonstration. Experientia designates the simple perception of singulars. Only in a very loose sense can it be used of scientific knowledge. Sometimes, however, these two terms about experience are used interchangeably. In this account, Bacon has not yet come to his later notion of a scientia experimentalis, and the experimental verification (certificatio) of the conclusions of demonstrative knowledge (ca. 1267). He is dealing only with experience as the source of the principles of our knowledge of art and science.]