Linguists of various theoretical backgrounds have likened second language (L2) acquisition to pidginization (Ferguson 1971, Richards 1971, Bickerton 1975a). This paper examines these two processes and suggests areas where a study of the process of second language acquisition in a natural setting might contribute insights to a general theory of linguistics. A distinction is made between L2 acquisition in a classroom situation and that in a natural setting without formal instruction, and the processes of the pidgin-creole-post-creole cycle as described in the literature are reviewed. A comparison of these situations reveals that while there is nothing in the L2 acquisition process analogous to creolization, the early stages of L2 acquisition are reminiscent of a pidgin. It also leads us to expect a continuum situation in natural L2 acquisition similar to that found in the decreolization process. The changes involved in second language acquisiton, however, can be expected to be more rapid and irregular than those of the pidgin-creole-decreolization continuum. A study of natural second language acquisition by adults can offer insights concerning both the notion of "simplified" speech and the psychological validity of constraints on rules which express language change. (Author)