Before embarking upon any study of "what is real", it is crucial to know where our knowledge comes from, and how reliable is that knowledge.  This task is known as epistemology.  The dictionary definition of epistemology is "the study or a theory of the nature and grounds of knowledge esp. with reference to its limits and validity".  The current state of epistemology is not useful, consisting of arduously convoluted distinctions such as the Gettier problem, and the unreasonable epistemologically privileged status of sense data, which is the dogma of science. Yet, epistemology should be simple and understandable by any ordinary person, as we all have personal access to knowledge.   In this chapter, I return to fundamentals and restrict epistemology to the study of the actual sources of all knowledge.  It will be argued here, and should be obvious, that knowledge comes from exactly three sources.  Each person receives knowledge from all three of these sources, and uses that knowledge to create a personal understanding, view, or model, of their world.  These three sources can be identified as the Physical, the Social, and the Personal. 

These three sources are inputs to the creation and development of the person's worldview, or Model.  In most cases, that Model is accepted as the basic truth of reality.   I present a more rational understanding of these three sources of knowledge, for the first time proving to a scientific certainty the validity of knowledge that cannot be expressed with language, and how each is used to create Models.  Though the Personal explanation is impossible to describe in words, I will argue that anyone, including physicists, must now agree to its reality, and how the necessary metaphors are understood only by those who have shared the experiences.