Existentialism Defined
 

Existentialism, philosophical movement or tendency of the 19th and 20th centuries.   Because of the diversity of positions associated with existentialism, a precise  definition is impossible; however, it suggests one major theme: a stress on   individual existence and, consequently, on subjectivity, individual freedom, and  choice.
Most philosophers since ancient Greek thinker Plato have held that the highest   ethical good is universal. Nineteenth-century Danish philosopher Soren Kierkegaard  reacted against this tradition, insisting that the individual's highest good is to find \par his or her own unique vocation. In terms of moral choice, existentialists have  argued that there is no objective, rational basis for decisions; they stress the   importance of individualism in deciding questions of morality and truth. Most  existentialists have held that rational clarity is desirable wherever possible but   that life's most important questions are not accessible to reason or science.

Freedom of choice, through which each human being creates his or her own nature,   is a primary theme. Because individuals are free to choose their own path,   existentialists have argued, they must accept the risk and responsibility of their  actions. Kierkegaard held that a feeling of general apprehension, which he called   dread, is God's way of calling each individual to commit to a personally valid way   of life. Relatedly, 20th-century German philosopher Martin Heidegger felt that  anxiety leads to the individual's confrontation with the impossibility of finding   ultimate justification for his or her choices.

The first to anticipate existentialism's major concerns was 17th-century French   philosopher Blaise Pascal, who denounced a systematic philosophy that presumes to   explain God and humanity. He saw life in terms of paradoxes: The human self,   combining mind and body, is itself a contradiction. Later, Kierkegaard rejected a   total rational understanding of humanity and history, stressing the ambiguity and  absurdity of the human situation.     Nineteenth-century German philosopher Friedrich Nietzsche espoused tragic  pessimism and life-affirming individual will. Heidegger argued that human beings  can never hope to understand why they are here; instead, each individual must   choose a goal and follow it with passionate conviction, aware of the certainty of  death and the ultimate meaninglessness of one's life. Twentieth-century French  philosopher Jean Paul Sartre first gave the term existentialism general currency  by using it for his own philosophy. Explicitly atheistic and pessimistic, his   philosophy declared that human life requires a rational basis but the attempt is a   "futile passion." Nevertheless, he insisted that his view is a form of humanism,  emphasizing freedom and responsibility.

Although it encompasses atheism and agnosticism, existentialist thought has had a  profound influence on 20th-century theology, addressing such issues as  transcendence and the limits of human experience, as well as a personal sense of  authenticity and commitment. Existentialism has been a vital movement in literature,   particularly in the works of Russian novelist Fyodor Dostoyevsky, Austrian writer  Franz Kafka, and French writer Albert Camus. It is also prominent in the theater of   the absurd, notably in the plays of Irish-born writer Samuel Beckett and   Romanian-born French writer Eugene Ionesco.
 

And Modern Existentialist and Phenomenological studies.....
 

  Since linguistic philosophy tends to be considered by its proponents to be a method  or a group of methods, internal diversity within the area of concern is not   surprising. Similarly, Existentialism, which is less of an "-ism" than an attitude,   expresses itself in a variety of ways. The most influential modern Existentialists have been the German philosopher Martin Heidegger (1889-1976) and the French   philosopher, dramatist, and novelist Jean-Paul Sartre (1905-80); the former was   especially important in the development of modern continental theology, particularly for the use made of some of his ideas by Rudolf Bultmann.
According to Heidegger, man's existence is characterized as "care." This care is  shown first in possibility: man makes things instrumental to his concerns and so   projects forward. Secondly, there is his facticity, for he exists as a finite entity   with particular limitations (his "thrownness"). Thirdly, man seeks to avoid the  anxiety of his limitations and thus seeks inauthentic existence. Authenticity, on the \par other hand, involves a kind of stoicism (positive attitude toward life and suffering)   in which death is taken up as a possibility and man faces the "nothing." The  structure of man's world as analyzed by Heidegger is revealed, in a sense,   affectively--i.e., through care, anxiety, and other existential attitudes and \par feelings.     Sartre's thought has had less direct impact on the study of religion, partly because  his account of human existence represents an explicit alternative to traditional \par religious belief. Sartre's analysis begins, however, from the human desire to be  God: but God is, on Sartre's analysis, a self-contradictory notion, for nothing can   contain the ground of its own being. In searching for an essence man fails to see   the nature of his freedom, which is to go beyond definitions, whether laid down by   God or by other human beings.
The French philosopher Gabriel Marcel (1889-1973) is not individualistic like   Sartre (or at least the early Sartre, whose thinking was modified by Marxism);  instead, he stresses the communal character of human existence--the highest virtue  being fidelity. Marcel also emphasizes the mysterious (as distinguished from the  empirically problematic) character of love, evil, hope, freedom, and, above all,   being. His work provides a rich analysis and interpretation of the religious   dimensions of human experience and thus is a philosophical basis for the study of    religious experience.
The Existentialist approach attempts to describe and evoke the way human beings  are and thus can lay claim to be phenomenological. It is clear, however, from the  divergencies among Existentialists, that they contain speculative and idiosyncratic   elements, and one question raised about the general applicability of their   characterizations is how far they are bounded by the product of a particular mood   in Western culture.   The German philosopher Edmund Husserl (1859-1938) has had, as the main  exponent of Phenomenology, a wide effect on the study of religion. His program of   describing experience and "bracketing" the objects of experience, in the pursuit   of essences of types of experience, was in part taken up in the phenomenology of  religion. Husserl distinguished Phenomenology from psychology, however, because,   in his view, the latter concerns facts in a spatio-temporal setting, whereas   Phenomenology uncovers timeless essences. This aspect of Husserl's thinking has   not always or wholly been accepted by phenomenologists of religion, who have   been much more oriented toward facts, though Husserl's emphasis on essences  often has tended to make religious phenomenology lean toward a static typology.

                                                                 --from Encyclopedia Britannica