John Clellon Holmes†and I were sitting around trying to think up the meaning of the Lost Generation and the subsequent Existentialism and I said,'You know, this is really a beat generation'and he leapt up and said,'That's it, that's right!'

-Kerouac,Jack (John)
  Interview in Playboy,  Jun.

L'homme n'est rien d'autre que ce qu'il se fait.Tel est le premier principe de l'existentialisme. Man is nothing else but that which he makes of himself. That is the first principle of existentialism.

-Sartre,Jean-Paul
  L'Existentialisme est un humanisme (Existentialism and Humanism,1948) (translated by Philip Mairet).