Has there ever been a civilization (if that is the right word) that didn’t believe in a higher power?
Civilizations don’t believe in anything; people do. I doubt there’s every been a civilization where anything like 100% of it’s members believed in anything.
An awful lot of folks in many civilizations today don’t believe in a higher power. Does that count? If not, what percent do you need?
Well, I’d be hard pressed to ever name a civilization that could believe anything. Civilizations don’t believe things, the people in them do.
That said, I can’t think of a civilization where religion was unknown, if that’s what you meant to ask.
ETA: Beaten to the punch with almost exactly the same wording! 
If you’re asking for a civilization where atheism was encouraged, the obvious answer would be various Communist countries during the twentieth century.
Many current Northern European countries have high percentages of atheists. I agree with the others that civilizations don’t hold beliefs and that groups of people aren’t monolithic entities.
Western Civilization it seems is moving toward this so I might have a firm yes in a hundred or perhaps even fifty years.
What exactly do you mean by a “higher power”? Neither Buddhism nor Confucianism, which have been the dominant belief systems of major cultures, are theistic in nature.
A lot of Confucians and Chinese Buddhists believed in the existence of T’ien or Heaven.
Does that constitute a “higher power”?
The OP is so vague that it’s going to be difficult to answer.
Confucius’ doctrine was explicitly agnostic. I forget the exact phrase, but he basically said, “Don’t ask me about the next world. I’m giving advice for this world.”
Chinese emperors, however, always claimed “The Mandate of Heaven” to justify their right to rule. One of the emperor’s titles was “Son of Heaven”. The state religion was polytheistic.
There are a whole lot of different Buddhist sects. A few deny the existence of deities. Most, however, meld with the local religion by classifying the local gods as buddhas or bodhisatvas.
Frederick the Great dabbled in athiesm when he was young. Once he inherited the Prussian throne, however, he publicly claimed to be a Christian.
A more interesting question would be where there are/were any tribes of humans without any notions of supernatural beings or forces.
Although I’m not sure what they mean by spirits. It seems like it’s all tangible things, but then why call them spirits?
Isn’t that description pretty much Animism?
I’m not sure if that would necessarily count as “believing in a higher power”; from my understanding at least some Buddhists don’t consider any gods to be higher powers.
Those people with bundles of incense bowing three times toward a temple full of statues of supenatural beings are worshiping something.
So you admit it. It’s TRUE…The fundies are right! We ARE moving towards a gawdless civilization! teh HORROR…teh HORROR!
More on the Piranha: http://www.edge.org/3rd_culture/everett07/everett07_index.html
Their religious skepticism was so strong they de-converted the missionary!
The simplicity of their language and religious beliefs makes me wonder it they went through a cultural bottleneck in the past. Is it possible a few young children survived a calamity that wiped out the rest of their tribe, then procreated and established a new culture without the complexities of language and religion they would have otherwise learned from their parents?
It’s a good idea to take anything said about the Pirahã with a grain of salt. So far everything we know about them is from what one person - Daniel Everett - says about them.
The original questioner assumes that his/her country, the USA, has a common set of beliefs based on religion. I assume he/she has such a religion. That kind of assumption is partly justified in the USA, but it is rare in other countries, apart from the fundamentalist Islamic states.
As another poster has pointed out, there is no such assumption in most of Europe. Freedom not to believe is fully accepted in public and private life. Non-believing public representatives do not make an absurd charade of pretending to be active Christians - certainly not in the way that has poisoned US public life with silly lies about religious practice.
However, surveys in Europe indicate that belief in life after death is common, even if it does not confrom to the Judaeo-Islamo-Chrisitian pattern. Many are post-Christian, but not non-religious. So, we see the rise of Druidism, Wicca and other older beliefs.
There appears to be a need in humans to believe in something after death, something more than life. It’s probably linked to an animal fear of death, and feeling that we lack of control over life. Even as we turn away from one set of beliefs, we seek another set to comfort us.
In Theravada the Buddha is an ordinary guy. Buddhahood is attainable by regular people. The buddha isnt worth worshipping or praying to as those who reach nirvana leave the suffering univese (samsara) and cannot communicate with it.
So yes, its still a religious system with supernatural ideas, but it exists with no creator gods and somewhat of an agnostic view. I wouldnt equate it with typical monotheistic worship, where you appeal to the creator for intervention or good luck via worship and praying.
That said, a lot of Buddhism inherits its cultural superstitions from whatever religion was there before, but its not a theistic system per se. In the Pali Canon, the Buddha discourages any talk about
As far as an atheistic culture goes, thats unheard of in human history. All pre-scientific explanations of the natural world are anthromorphized, so most cultures have some kind of gods, demons, spirits, animating force, during some level of development. This has not gone away, even after the enlightenment.