Francis Crick, famous for co-discovering (with James D. Watson) the structure of the DNA molecule, was an English molecular biologist and neuroscientist. Crick was an outspoken critic of religion, and an advocate of the view that the mind is simply a product of the physical brain. He held that the new findings of the neurosciences would eventually replace mistaken religious conceptions of the nature of human beings, a position he elaborates in his popular work The Astonishing Hypothesis: The Scientific Search for the Soul (1994). Although strictly speaking an agnostic, he was profoundly sceptical of organised religion and claimed to have had a 'strong inclination' towards atheism.
Alfred Ayer was a British philosopher and promoter of logical positivism. Ayer, an outspoken atheist, was closely involved with the British humanist movement. In 1965 he succeeded Julian Huxley as the president of the British Humanist Association, a position which he held until 1970. In 1989, shortly before his death, Ayer had a Near Death Experience, which he claimed had weakened but not changed his belief in the finality of physical death.
Bertrand Russell was a British philosopher and prominent critic of religion. Russell had scruples about describing himself as an atheist as opposed to an agnostic in the strictest philosophical sense, but preferred to describe himself as an atheist in most contexts. Russell held that religion is a mere superstition, and largely harmful in its effects. Russell's views of religion are summarised in his popular work Why I am not a Christian (1927). Russell was of the view that religion was based primarily on fear.
Vladimir Ilyich Ulyanov, better known as Lenin, was a Russian revolutionary, the main leader of the Russian Revolution, and from 1922 the first leader of the Soviet Union. He was the founder of Marxist-Leninism, an extension of Marxist theory. Marxist-Leninism was atheistic, and openly hostile towards all religion. In 1921 Lenin instigated an offensive campaign against religion which would set the model for future Soviet attacks on religion (see also Stalin).
Josef Dzhugashvili better known as Joseph Stalin, was General Secretary of the Soviet Communist Party from 1922 until his death in 1953. Stalin's forced industrialisation of Russia in the 1930s and his campaigns of political repression led to the deaths of millions of people. The Russian Orthodox Church was continuously persecuted in the 1930s and driven almost to extinction. Many churches were destroyed, and tens of thousands of priests, monks and nuns were killed.
Ayn Rand was a Russian-born American novelist and philosopher. Rand, a committed individualist, founded the philosophy of Objectivism, and was a passionate advocate of laissez-faire capitalism. As a rationalist, Rand rejected religion, believing that it militated against the individualist pursuit of happiness and the successful and efficient functioning of a capitalist society.
Sir Julian Huxley, the grandson of 'Darwin's bulldog' Thomas Huxley , was an English evolutionary biologist and humanist. Huxley was not a strict atheist but rather an agnostic; however, his humanist views have exerted a very appreciable direct or indirect influence on subsequent atheists down to Richard Dawkins. Closely associated with the main British secular societies and movements, Huxley was the first President of the British Humanist Association from its foundation in 1963 until 1965 when he was succeeded by A.J.Ayer. He was also closely involved with the International and Humanist Ethical Union.
John Leslie Mackie was an Australian philosopher. Alongside Anthony Flew he was probably the foremost philosophical atheist of his generation. Mackie considered that the problem of evil undermined the claims of the Abrahamic religions and that classical free will defences did nothing to excuse the existence of evil and suffering in the world.
Sigmund Freud was the founder of psychoanalysis. He believed that religion had a baleful effect on society, and offered various reductive explanations of religion in his writings. Freud's psychological explanation of religion - namely, that God is a projection of the Unconscious - is indebted to the projection theory of Feuerbach. For both Feuerbach and Freud, religion is a form of wish-fulfilment. Freud regarded religion as fundamentally neurotic.
Jean-Paul Sartre was a French existentialist philosopher as well as a dramatist, novelist and critic. In contrast with other contemporary existentialists such as the Christian Gabriel Marcel, Sartre advocated a form of atheist existentialism, according to which there was no God and human beings were radically free to shape their existences in any way they chose.
Jacques Monod was a French biologist who was awarded the 'Nobel Prize in Physiology or Medicine in 1965'. In Chance and Necessity (1971) Monod elaborated an entirely non-providential view of the biological world as the mere product of chance and necessity, and proposed that the natural sciences reveal a purposeless world which entirely undercuts the tradition claims of religions.