After World War 1 was over, science changed. Science had become so complicated regular people had trouble understanding it. Ideas like time, space, and motion used to make sense. People used to believe the humans were logical. However; new scientists like Albert Einstein began saying that the only thing that did not change was the speed of light. Things like space and time were flexible and could bend. Thinkers like Sigmund Freud said that people's minds had a lower, almost secret level called the unconscious. Freud's ideas weakened people's faith in ___________________.