This chapter narrates how in the wake of a resurgence of Marxist Enlightenment in European universities in the 1970s, the Danish general psychology project was greatly facilitated by the discovery of Lev S. Vygotsky and his Cultural-historical activity theory school. In particular, how Alexei N. Leontiev's psycho-phylogenetic activity model as a virtual mirror image of Aristotle's bio-psychological taxonomy became a key? The author's suggested model of general psychology is a combination of Aristotle's and Leontiev's models and presented in the end.