Wundt saw examples of human self-education in walking upright, physical facilities and "an interaction in part forced upon people by external conditions and in part the result of voluntary culture".Wundt, Völkerpsychologie. Vol. 10, p. 189. He described the random appearance and later conscious control of fire as a similar interaction between two motives. In the interaction of human activity and the conditions of nature he saw a creative principle of culture right from the start; tools as cultural products of a second nature. An interactive system of cause and effect, a system of purposes and thus values (and reflexively from standards of one's own activities) is formed according to the principles of one's own thinking.Wundt, Völkerpsychologie. Vol. 10, p. 195.
