Wundt was a determinist. That is, he did not believe in free will. Behind all volitional acts were mental laws that acted on the contents of consciousness. These laws were unconscious, complex, and not knowable through either introspection or other forms of experi- mentation; but laws they were, and their products were lawful. According to Wundt, the laws of mental activ- ity can be deduced only after the fact, and in that sense the psychologist studying them is like a historian:
Future resultants can never be deter- mined in advance; but … on the other hand it is possible, starting with the given resultants, to achieve, under favourable conditions, an exact deduction into the components. The psychologist, like the psychological historian, is a prophet with his eyes turned towards the past. He ought not only to be able to tell what has happened, but also what necessarily must have happened, according to the position of events. (Wundt, 1912/1973)
The historical approach must be used to inves- tigate the higher mental processes, and it is that approach that Wundt used in his Völkerpsychologie, to which we turn next.