‘Conscience’ is a slave driver, put into man by himself. It drives him with harshness and cruelty, forbidding him pleasure and happiness, making his whole life the atonement for some mysterious sin.
Fromm argues that the modern ‘conscience’ is not an authentic moral faculty but an internalization of external social demands that operates with harshness and cruelty, structurally replicating the oppressor within the self.
, Escape from Freedom, 1941thesis