Ever since Bickerton (1974Bickerton ( , 1981Bickerton ( , 1984aBickerton ( , 1984b posited similarities in the tense, mood, and aspect (TMA) systems as evidence for a linguistic-universal explanation of creole genesis, TMA has been the pre-eminent locus for the discussion of shared properties of creoles and for the debate about their origins. Particularly after Roots of language (1981), scholars began to question Bickerton's (B's) explanations, and set out to find alternative answers to the striking similarities among creoles, particularly the TMA systems. Undermining B's bioprogrammatic arguments has not been easy, inasmuch as methodological constraints introduced by B himself have complicated the task considerably. Clinging to the argument that the setting for the genesis of creoles is characterized by chaos and by severely limited access to the target language, B has dismissed out of hand other scholars' counterarguments because the creoles on which they were based developed in more fixed social settings that allowed the child learners to acquire certain features from the speech of their parents rather than from the language bioprogram. (In 1984a, B refines further the notion of "more or less bioprogrammatic creole," and proposes an implicational scale for the degree of "radicalness" of creoles.) While scholars have generally conceded that B may be fundamentally correct in claiming that the degree of linguistic deprivation, and, therefore, the reliance on a language bioprogram may, in fact, vary in relation to the learners' access to stratal languages, they have also been quick to point out problems which seriously weaken the force of his bioprogrammatic explanation for the shared TMA properties of creoles. There are four major objections: