[1]Vygotsky appears to draw heavily on Münsterberg's ideas about unification in practices as the requirement for uniting the two kinds of psychology Münsterberg (1914):" Unification is reached in applied psychology which speaks of the practical application of mental facts in the service of human purposes. The selection of these purposes is a matter of purposive psychology, the mental effects to be used a matter of causal psychology. They are thus joined in that practical part which comes nearest to real life (p. 16)."