Transderivational Correspondence and Uniform Exponence are two recent theories of surface resemblances among morphologically related words. This article describes the Optimal Paradigms theory, which incorporates elements of both. In OP, candidates consist of entire inflectional paradigms. Within each candidate paradigm, there is a correspondence relation from every paradigm member to every other paradigm member. Faithfulness constraints on this intraparadigmatic correspondence relation resist alternation within the paradigm. This model is illustrated and supported with a type of evidence that has not figured in previous discussions, the templatic structure of the Classical Arabic verb. Generalized Template Theory demands that templatic restrictions emerge from independently motivated constraints. The OP model supplies this kind of explanation for the permitted shapes of Arabic verbal templates.