New Atheism is the name given to the ideas promoted by a collection of 21st-century atheist writers who have advocated the view that "religion should not simply be tolerated but should be countered, criticized, and exposed by rational argument wherever its influence arises."

The term is commonly associated with individuals such as Richard Dawkins, Daniel Dennett, Sam Harris, and the late Christopher Hitchens (together called "the Four Horsemen of New Atheism" in a 2007 debate they held on their criticisms of religion, a name that has stuck) and Victor J. Stenger. Several best-selling books by these authors, published between 2004 and 2007, form the basis for much of the discussion of new atheism.

The 2004 publication of The End of Faith: Religion, Terror, and the Future of Reason by Sam Harris, a bestseller in the USA, marked the first of a series of popular bestsellers. Harris was motivated by the events of September 11, 2001, which he laid directly at the feet of Islam, while also directly criticizing Christianity and Judaism. Two years later Harris followed up with Letter to a Christian Nation, which was also a severe criticism of Christianity. Also in 2006, following his television documentary The Root of All Evil?, Richard Dawkins published The God Delusion, which was on the New York Times bestseller list for 51 weeks. Other milestone publications include Breaking the Spell: Religion as a Natural Phenomenon by Daniel C. Dennett (2006); God: The Failed Hypothesis – How Science Shows That God Does Not Exist by Victor J. Stenger (2007); God Is Not Great: How Religion Poisons Everything by Christopher Hitchens (2007); Atheist Manifesto: The Case Against Christianity, Judaism, and Islam by Michel Onfray (2007); and Godless: How an Evangelical Preacher Became One of America's Leading Atheists by Dan Barker (2008).

Clinton Richard Dawkins, FRS, FRSL (born 26 March 1941), known as Richard Dawkins, is a British ethologist, evolutionary biologist and author. He is an emeritus fellow of New College, Oxford, and was the University of Oxford's Professor for Public Understanding of Science from 1995 until 2008.

Dawkins came to prominence with his 1976 book The Selfish Gene, which popularised the gene-centered view of evolution and introduced the term meme. In 1982 he introduced an influential concept into evolutionary biology, presented in his book The Extended Phenotype, that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, including the bodies of other organisms.

Dawkins is an atheist, a vice president of the British Humanist Association, and a supporter of the Brights movement. He is well known for his criticism of creationism and intelligent design. In his 1986 book The Blind Watchmaker, he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the complexity of living organisms. Instead, he described evolutionary processes as analogous to a blind watchmaker. He has since written several popular science books, and makes regular television and radio appearances, predominantly discussing these topics. In his 2006 book The God Delusion, Dawkins contends that a supernatural creator almost certainly does not exist and that religious faith is a delusion—"a fixed false belief." As of January 2010 the English-language version has sold more than two million copies and had been translated into 31 languages.

Hamza Yusuf Hanson is an American Islamic scholar, and (with Zaid Shakir and Hatem Bazian) is co-founder of Zaytuna College in Berkeley, California, United States. He is a convert to Islam, and is one of the signatories of A Common Word Between Us and You, an open letter by Islamic scholars to Christian leaders, calling for peace and understanding. He has described the 9/11 attacks as "an act of 'mass murder, pure and simple'". Condemning the attacks, he has also stated "Islam was hijacked ... on that plane as an innocent victim".The Guardian newspaper in the United Kingdom reported that he "is arguably the west's most influential Islamic scholar" and added that "many Muslims find his views hard to stomach."

Hamza Yusuf was born to two academics in Washington State and raised in Northern California. In 1977, he became Muslim and subsequently traveled to the Muslim world and studied for ten years in the United Arab Emirates, Saudi Arabia, as well as North and West Africa. Hamza Yusuf spent four years studying in the United Arab Emirates and elsewhere in the Middle East. Later he traveled to West Africa and studied in Mauritania, Medina, Algeria, and Morocco under such scholars as Murabit al Haaj; Baya bin Salik, head of the Islamic court in Al-'Ain, United Arab Emirates; Muhammad Shaybani, Mufti of Abu Dhabi; Hamad al-Wali; and Muhammad al-Fatrati of Al Azhar University in Cairo, Egypt.^{[citation needed]} After more than a decade abroad, he returned to the United States and earned degrees in nursing from Imperial Valley College and religious studies at San José State University.^{[citation needed]}