The Dutch painter Hieronymus Bosch imagined a world with no religion in his iconic painting "The Garden of Earthly Delights," depicted above (click here for high resolution image). The central panel of the triptych shows "how humanity would be without a fall, living in paradise without knowledge of right and wrong," says the Dutch/American biologist Frans de Waal, who was born in the same city as Bosch and sees the artist as part of a very long humanist tradition in the Netherlands that goes back to Erasmus and Spinoza.
Waal argues that moral behavior is a product of evolution in his book, The Bonobo and the Atheist: In Search of Humanism Among the Primates, which explores examples of altruistic behavior in primates such as chimpanzees. So could mankind be altruistic without religion? Waal sees Bosch's painting as the perfect illustration of humanism. "Some people find those paintings morbid or horrifying," he tells us, "and that’s because he showed Hellish scenes. But actually The Garden of Earthly Delights, most of that painting is delightful."
Waal has in mind the "Bonobo-like situation where people frolic around" in the central panel. "There’s actually a thousand people in that middle part who are having sex or having other adventures going on," Waal points out. That's what humanity would look without God and without religion.
I’m basically a humanist myself and I use Bosch to illustrate primate-like tendencies because he often illustrates them. How people share fruits and how people have sex and how people do wrong things or right things in his paintings. And so Bosch sort of depicts, for me, a visualization of the moralization that may come about if you’re not necessarily religious.
Could such a world exist today? "I’m struggling with whether we need religion," Waal says. "Personally I think we can be moral without religion because we probably had morality long before the current religions came along."
Waal says there is an experiment going on in northern Europe Waal right now. The majority of people there are not religious. They say they’re nonbelievers. "They still have a moral society as far as I can tell," Waal says. "It may be present but it’s not dominant anymore, and there is still a moral society. And so I am optimistic that religion is not strictly needed. But I cannot be a hundred percent sure because there is no human society where religion is totally absent so we really have never tried this experiment."