This introductory chapter will briefly delineate the theory of cognitive niche construction, on which this part will extensively rely. Cognitive niche construction is a theoretical framework that is proving extremely profitable in bridging philosophy, cognitive science, biology and anthropology studies by offering a real inter-disciplinary ground affording novel approaches to long debated issues in several fields. In brief, it concerns the ability, displayed by human beings and other organisms, to affect their own evolutive processes by cognitively shaping their environment in order to modify the selective pressure the latter has on them. Thus, a second hereditary system is introduced, afforded by the ecological persistence of knowledge externalizations serving as cognitive aids.