This paper explores the status of parameters within the current Minimalist Program, with special reference to its consequence to diachronic parametric change. After a brief review of the history of generative grammar since Chomsky (1981), the following notions of parameters are put in order: syntactic versus lexical parameters, deep versus surface parameters, and macro versus micro parameters. It is argued that under the tenet of the Strong Minimalist Thesis, only lexical parameters are allowed, and that they are divided into deep parameters in the Lexicon and surface parameters in the Vocabulary. An immediate consequence of this dichotomy is that it enables us to approach the logical problem of language change in a technically feasible fashion. Specifically, given that surface parameters are subject to change in adult grammars, diachronic parameter resetting can be explained by means of interactions between surface changes in the Vocabulary and deep changes in the Lexicon. The validity of this dynamic model is demonstrated by reconsidering the loss of verb movement in the history of English, which is loosely related to the decline of verbal inflections.