Abstract
In two studies, children's concepts of various types of ordinarily unobservable entities were examined. Study 1 confirmed earlier findings in showing that children aged 4–9 years are confident of the existence of scientific entities such as germs as well as religious beings such as God. At the same time, both age groups are skeptical of the existence of various mythical beings such as mermaids. In Study 2, older children aged 10–12 years were probed for their concepts of religious as compared to scientific phenomena. Despite considerable confidence in each type, older children differentiated between them, both with respect to their level of confidence and their pattern of justification.