The authors of this article suggest their own definition of knowledge by presence as the kind of knowledge that only reveals itself to the knower, visa-vis knowledge by representation that reveals something else too. They believe that this definition is more suitable to the reality of knowledge by presence as an existential entity, because revealing is the most ontologically essential trait of any knowledge, and knowledge by presence is nothing other than being, and presence, of the known for the knower. Knowledge in nothing other than the disclosure of the known for the knower, and disclosure becomes possible by presence and presence by unity or identification. Therefore, whenever there is unity or identification, there will be knowledge by presence too. Different types of unity bring about different kinds of knowledge by presence such as knowledge of the self, of the attributes, of the accidents and affections, of the faculties and existential stages, of the body, etc.