Publisher Summary This chapter outlines the basic principles of knowledge representation and decides an initial representation language. The task of the chapter is to create a knowledge base (KB) that contains appropriate entailments in first-order logic (FOL). In creating a KB it is a good idea to start with the set of domain-dependent predicates and functions that provide the basis for the statement of facts about the KB's domain. The most obvious place to start is with the named individuals who are the actors in human drama. In FOL, these would be represented by constant symbols, like mary Jones, johnQSmith, and so on. The FOL language gives the basic tools for representing facts in a domain, but in many cases there is a great deal of flexibility that can be exercised in mapping objects in that domain onto predicates and functions. Another class of named individuals would be the legal entities that have their own identities, such as corporations (faultylnsuranceCompany), governments (evilvilleTownCouncil), and restaurants (theRackAndRollRestaurant.