This Venn diagram sample illustrates the Plato's definition of knowledge. It was designed on the base of the Wikimedia Commons file: Belief Venn diagram.svg. [commons.wikimedia.org/wiki/File:Belief_Venn_diagram.svg]
"Justified true belief is a definition of knowledge that is most frequently credited to Plato and his dialogues. The concept of justified true belief states that in order to know that a given proposition is true, one must not only believe the relevant true proposition, but one must also have justification for doing so. In more formal terms, a subject S knows that a proposition P is true if and only if:
(1) P is true,
(2) S believes that P is true, and
(3) S is justified in believing that P is true" [Justified true belief. Wikipedia]
The Venn diagram example "Knowledge" was created using the ConceptDraw PRO diagramming and vector drawing software extended with the Venn Diagrams solution from the area "What is a Diagram" of ConceptDraw Solution Park.