Many will question Bickerton's claim that only humans are capable of mentalengagement with anything but the immediate present. However, the heart of hisargument—that language did not evolve as a development from high intelligence but isinstead what allowed that intelligence to develop at all—is undeniably compelling. Underthis conception, the emergence of language, not just intelligence, was what allowed humans toconquer the world. In support, Bickerton notes that the appearance of modern civilization waspreceded by eons by cultural stasis during which hominid brains were nevertheless increasingvastly in size, which suggests that something besides mere brain power created modern man. Healso notes that if human-like intelligence allowed world domination, then at least some animalsshould by now have developed it, even without language. Instead, only humans can profoundlyalter their surroundings, which suggests that language, the trait most unequivocally unique tohumans, is indeed the key to our hegemony. Bickerton even equates language and thought,arguing that their foundation upon the same syntax leaves no motivation to separate them, andconsiders both to evidence a layer of abstract representation unique to humans. In turn, heproposes that this layer is able to “observe” the lower layer, thus creating“consciousness.” The uniqueness of consciousness to humans is thus explained byits roots in a layer of representation unique to humans.