This is how the thinking layer of the Earth as we know it today—the noösphere—came rapidly into being, proceeding from certain centers of reflection which apparently emerged at the threshold of the Pleistocene Age somewhere in the tropical or sub-tropical spheres of the Ancient World (i.e., in the place where, during the Upper Tertiary Period, the group of the great anthropoids was first established and subsequently spread.): a planetary neo-envelope, essentially linked with the biosphere in which it has its root, yet distinguished from it by an autonomous circulatory, nervous, and finally, cerebral system. The noösphere: a new stage of life renewed.