"The Copernican revolution... revealed that the earth is not the center of the universe... The second, the Darwinian revolution... revealed that we are not created divinely or uniquely but instead evolved from simpler animals by a process of natural selection. The third great revolution, the Freudian revolution of Vienna 1900, revealed that we do not consciously control our own actions but are instead driven by unconscious motives. This... later led to the idea that human creativity... stems from conscious access to underlying, unconscious forces."