Religion as social control
Karl Marx's idea of 'religion is opium of the people', how it oppresses the workers as well as making them feel better about being oppressed.
Religion as ritual
Sociologist (Isidore) Auguste (Marie François Xavier) Comte's idea of how religion develops along with science, and that ritual becomes an important part of society in the process.
Religion as a mother
Swiss antiquarian and Roman law professor J. J. Bachofer’s theories of matriarchy.
Religion as a virus
Atheist and evolutionary biologist Richard Dawkin's idea of religion as a virus, spread through 'memes'.