"Religious suffering is, at one and the same time, the expression of real suffering and a protest against real suffering. Religion is the sigh of the oppressed creature, the heart of a heartless world, and the soul of soulless conditions. It is the opium of the people." (From the "Introduction to the Critique of Hegel's Philosophy of Right," 1843)

Khalil Hamra/AP
An Egyptian woman attends Friday prayers before a rally in Tahrir Square to denounce the presidential candidacies of Hosni Mubarak-era officials, in April, 2012.