1807 German philosopher Georg Hegel says that our ideas and values are fashioned by the zeitgeist, or spirit of the age, which constantly changes through the reconciliation of opposing views.
1927 German physicist Werner Heisenberg’s “Uncertainty Principle” reveals that the observer affects the observed.
1973 American psychologist Kenneth Gergen writes Social Psychology as History, which marks the emergence of social constructivism.
1978 In his zone of proximal development theory, Lev Vygotsky puts forward the idea that learning is fundamentally a socially mediated activity.
In the late 1960s, some ...