This paper describes how high-level of Object-Oriented concepts can be used to provide a generic, portable and polymorphic Fuzzy Logic framework. It highlights the way in which such OO concepts allow the extension of the programming language idioms with the semantics of the fuzzy logic field. A progressive approach presents; in a first step Fuzzy Logic systems; then, relevant classes, design patterns and architectures are identified. The considered aspects cover the composite structure, the polymorphic behaviour and the building of a system of fuzzy expressions. Finally, an example illustrates how the framework can be used in a conventional design strategy.