Jean-Paul Sartre is a well-known French philoso­pher who was con­cerned with human authen­tic­i­ty and indi­vid­u­al­i­ty. His nov­el Nau­sea is, in some ways, a man­i­festo of athe­is­tic exis­ten­tial­ism.

Dennett is an athe­ist and sec­u­lar­ist, a mem­ber of the Sec­u­lar Coali­tion for Amer­i­ca advi­so­ry board, and a mem­ber of the Com­mit­tee for Skep­ti­cal Inquiry, as well as an out­spo­ken sup­port­er of the Brights move­ment. Den­nett is referred to as one of the “Four Horse­men of New Athe­ism”, along with Richard Dawkins, Sam Har­ris, and the late Christo­pher Hitchens.

Russell claimed that begin­ning at age 15, he spent con­sid­er­able time think­ing about the valid­i­ty of Chris­t­ian reli­gious dog­ma, which he found very uncon­vinc­ing. At this age, he came to the con­clu­sion that there is no free will and, two years lat­er, that there is no life after death. Final­ly, at the age of 18, after read­ing Mill’s “Auto­bi­og­ra­phy”, he aban­doned the “First Cause” argu­ment and became an athe­ist.

During Arsuzi’s study­ing at Insti­tut Laïc his athe­ism became noto­ri­ous, and he was often caught say­ing “Sons of Earth are more capa­ble of direct­ing their affairs than sons of heav­en.”

Harris has been referred to, along with Daniel Den­nett, Richard Dawkins, and Christo­pher Hitchens, as one of the “new athe­ists”, but he con­sid­ers the term “athe­ist” to be prob­lem­at­ic. He said, “while I am now one of the pub­lic voic­es of athe­ism, I nev­er thought of myself as an athe­ist before being induct­ed to speak as one […] I think that ‘athe­ist’ is a term that we do not need, in the same way that we don’t need a word for some­one who rejects astrol­o­gy.”

Aval­os is an athe­ist and advo­cate of sec­u­lar human­ist ethics, and a for­mer Pen­te­costal preach­er and child evan­ge­list.

The state­ment “God is dead”, occur­ring in sev­er­al of Nietzsche’s works (notably in The Gay Sci­ence), has become one of his best-known remarks. On the basis of it, most com­men­ta­tors regard Niet­zsche as an athe­ist.

Marx was an athe­ist from his child­hood and remained such for the whole of the rest of his life.

His athe­ism was not only prac­ti­cal but also the­o­ret­i­cal. His the­o­ret­i­cal athe­ism is due pri­mar­i­ly to philo­soph­i­cal rea­sons and only sec­on­dar­i­ly to his­tor­i­cal, social and polit­i­cal rea­sons.

Already in his the­sis for the doc­tor­ate Marx pro­claims in no uncer­tain terms that “in the coun­try of rea­son” the exis­tence of God can­not have any mean­ing.