diffusion of Existentialism

From 1940 on, with the diffusion of Existentialism through continental Europe, its directions have developed in terms of the diversity of the interests to which they are subject: the religious interest, the metaphysical interest, the moral and political interest. This diversity of interests is rooted, at least in part, in the diversity of sources on which Existentialism has drawn. One such source has been the subjectivism of the 4th"5th-century theologian St. Augustine, who exhorted man not to go outside himself in the quest for truth, for it is within him that truth abides. “If you find that you are by nature mutable,” he wrote, “transcend yourself.” Another source has been the Dionysian Romanticism of Nietzsche, who exalted life in its most irrational and cruel features and made this exaltation the proper task of the “higher man,” who exists beyond good and evil. Still another source has been the nihilism of Dostoyevsky, who, in his novels, presented man as continually defeated as a result of his choices and as continually placed by them before the insoluble enigma of himself.



i don't understand these english word meaning "Existentialism" and "subjectivism" .

Can someone please explain in simple words ...what are these ?