 For the constructive empiricist, this characterization is “not meant as a definition, but only as a rough guide to the avoidance of fallacies” (van Fraassen 1980, 16). It is important to clarify that, as a constructive empiricist would use the terminology, one only observes something when the observation is unaided. One does not see cells through a microscope; instead one sees an image, an image which the scientific gnostic understands one way but the scientific agnostic understands a different way.