Sam Harris, author of books like The End of Faith and one of the so-called "Four Horsemen of New Atheism," has just announced his next book—ressurecting a long-running debate among atheists.

Waking Up: A Guide to Spirituality Without Religion, set to be published in September, will explore nonreligious spirituality. In 2012 Harris wrote that his goal for this book was "to write a 'spiritual' book for smart, skeptical people — dealing with issues like the illusion of the self, the efficacy of practices like meditation, the cultivation of positive mental states, etc."

With Waking Up's impending publication, many in the atheist community will debate whether it makes sense for atheists to use the word spirituality. But this isn't the first time this question has come up in recent years.

Last year Oprah Winfrey ignited a firestorm among atheists when, during an interview, she challenged distance swimmer Diana Nyad's claim that she is an atheist. But Nyad defended her perspective, arguing that she is both an atheist and a spiritual person.

"I think you can be an atheist who doesn’t believe in an overarching being who created all of this and sees over it," Nyad said to Winfrey. "But there's spirituality because we human beings, and we animals, and maybe even we plants, but certainly the ocean and the moon and the stars, we all live with something that is cherished and we feel the treasure of it."

Nyad is one of a number of nontheists to argue for atheist spirituality. In 2008 philosopher André Comte-Sponville published the well-recieved The Little Book of Atheist Spirituality. And in The Demon-Haunted World: Science as a Candle in the Dark, agnostic astronomer Carl Sagan offered this defense of naturalistic spirituality:

Despite usage to the contrary, there is no necessary implication in the word "spiritual" that we are talking of anything other than matter (including the matter of which the brain is made), or anything outside the realm of science. On occasion, I will feel free to use the word. Science is not only compatible with spirituality; it is a profound source of spirituality. When we recognize our place in an immensity of light years and in the passage of ages, when we grasp the intricacy, beauty and subtlety of life, then that soaring feeling, that sense of elation and humility combined, is surely spiritual.

Adam Lee, atheist activist and author of the 2012 book Daylight Atheism, published an essay in 2005 defending atheist spirituality—and he continues to argue for its merit.

"Spirituality is just another term for the human feelings of awe and wonder, which are common to atheists and the religious alike," Lee said in a recent interview. "Historically, religion claimed to be the sole source of these feelings, but atheists know we can also feel them from simply contemplating the mystery and vastness of the cosmos and the strange beauty of the world in which we find ourselves. The natural world is at least as good a source of transcendent bliss as any religious belief."

A number of nontheists disagree. At About.com, Austin Cline addresses some of the atheist arguments for and against the use of the word, raising the issue that many see the word as being problematically vague or too associated with religion. David Silverman, president of American Atheists, agrees that is misleading.

"Spirituality is one of those double-meaning words... It's no better than calling yourself 'religious,' because that's what religious people hear," said Silverman. "I choose to convey the truth. I am compassionate. I am empathetic. I am good. But I am not 'spiritual' in any way that a theist would interpret."

David Webster, University of Gloucestershire professor and author of the 2012 book Dispirited: How Contemporary Spirituality Makes Us Stupid, Selfish and Unhappy, also thinks nontheists should avoid the word.

"The term is too muddled—caught up with assertions of 'spirit,' weighed down by metaphysical baggage, and open to both innocent and willful misinterpretation," Webster said in a recent interview. "Atheistic spirituality seems to offer a way to assert an appreciation of nature, of interconnectedness and wonder... [But] do we need the 'spiritual' tag to do that? Aren't these appreciations, realizations, and connections just part of what, for an atheist, it means to be a human being? Let's leave 'spirituality' to those that believe in the spirit."

Webster suggests that, in some cases, atheists using the language of spirituality may be trying to express commonality with theists. But he proposes another way.

"There is something, I feel, more bold and heartening about resisting the temptation of [claiming 'spirituality' as] shared ground with faith-traditions when we don't mean the same things they do by the term. If we are to share things between atheism and faith-traditions, let's do so not on some confused, muddled shared wonder at sunsets, but on real issues where we genuinely share concerns—like social justice, wealth inequity, poverty, and the environment."

What do you think, readers? Are you a nontheist who uses the term "spiritual"? Are you a nontheist who doesn't? Why or why not?