The first existentialist was not Sartre, though he coined the term. Nor was it Kierkegaard or Nietzsche, though most of the textbooks say so. Nor was it even Pascal, though he foreshadowed half of Kierkegaard and was the first to write about the fundamental existential experience of cosmic anxiety and meaninglessness. It was not even Saint Augustine, whose Confessions stands out as the profoundest example of depth psychology and existential autobiography ever written. It was not even Socrates, who alone among philosophers totally existed his philosophy.
Rather, the first existentialist was Solomon, or whoever wrote Ecclesiastes.

Schopenhauer was not the only one of Hegel’s opponents to rest his faith in the unsayable. Soren Kierkegaard (1813-1855), in his attack on the prevailing Hegelian rationalism, sought to undermine the claim that ‘the real is the rational and the rational the real’, and so to reaffirm the value of that which, while real, lies beyond the reach of reason. But, lacking Schopenhauer’s gift of argument, and being indeed more literary than philosophical in his inclination, he did not set up any elaborate system of ideas whereby to postpone the recognition of his ultimate refuge. His principal interest was the vindication of the Christian faith, and he wrote directly or indirectly towards this end, inventing in the process the name, if not the philosophy of ‘existentialism’, for which achievement he is now chiefly known. His philosophy is a clear example of a reaction against idealism which is not also a form either of empiricism or skepticism. In the course of this reaction, it is once again the subject that is reaffirmed, as the ground of all philosophical thought.

The prideful, rational mind, comfortable with its certainty, enamoured of its own brilliance, is easily tempted to ignore error, and to sweep dirt under the rug. Literary, existential philosophers, beginning with Søren Kierkegaard, conceived of this mode of Being as “inauthentic.” An inauthentic person continues to perceive and act in ways his own experience has demonstrated false. He does not speak with his own voice.

What an existential approach is about is positing that our bad feelings, our dysphoria, our despair, our anxiety emanates not only from our own life history and all the traumas we may have had in the past, and not only from the figures that we have introjected — many of these figures being unloving, or uncaring, or neurotic on their own parts — and emanates not only from our current life crises, but it emanates also, also, from our confrontation with the existential facts of life, with our confrontation with the human condition.

The existential attitude is one of involvement in contrast to a merely theoretical or detached attitude. “Existential” in this sense can be defined as participating in a situation, especially a cognitive situation, with the whole of one’s existence.

Nietzsche was not an Existentialist. Existentialism emerged out of the conflict between Nietzsche and Kierkegaard, the Danish religious writer.

Existentialism is no mournful delectation but a humanist philosophy of action, effort, combat, and solidarity. Man must create his own essence: it is in throwing himself into the world, suffering there, struggling there, that he gradually defines say what this man is before he dies, or what mankind is before it has disappeared.

Existentialism is nothing else but an attempt to draw the full conclusions from a consistently atheistic position. Its intention is not in the least that of plunging men into despair. And if by despair one means as the Christians do – any attitude of unbelief, the despair of the existentialists is something different. Existentialism is not atheist in the sense that it would exhaust itself in demonstrations of the non-existence of God. It declares, rather, that even if God existed that would make no difference from its point of view. Not that we believe God does exist, but we think that the real problem is not that of His existence; what man needs is to find himself again and to understand that nothing can save him from himself, not even a valid proof of the existence of God. In this sense existentialism is optimistic. It is a doctrine of action, and it is only by self-deception, by confining their own despair with ours that Christians can describe us as without hope.

Kierkegaard, Nietzsche, and those who followed them accurately foresaw this growing split between truth and reality in Western culture, and they endeavored to call Western man back from the delusion that reality can be comprehended in an abstracted, detached way. But though they protested vehemently against arid intellectualism, they were by no means simple activists. Nor were they antirational. Anti-intellectualism and other movements in our day which make thinking subordinate to acting must not at all be confused with existentialism. Either alternative-making man subject or object-results in loosing the living, existing person.

Existentialism
“every appearance in nature corresponds to some state of the mind,” we have entered the familiar Wordsworthian Romantic territory in which nature is phenomena and spirit is noumena and the task of the human person is to draw his being from whatever inscrutable force produces, organizes, and infuses the phenomenal universe — an “ineffable essence which we call Spirit. Being as not being stable but forever in flux and transition. Even history, Which seems obviously about the past, has its true use as the servant of the present.' Emerson and Buddhism stand for spirituality purged of creed detritus.' the essence of Existentialism is that you find meaning in nature, wisdom, mind and body.

When Shaw is read in the light of the existentialist thinkers, a new philosophical position arises from his works as a whole, a position of he himself was probably unconscious. It is this: that although the ultimate reality may be irrational, yet man's relation to it is not. Existentialism means the recognition that life is a tiny corner of casual order in a universe of chaos. All men are aware of that chaos; but some insulate themselves from it and refuse to face it. These are the Insiders, and they make up the overwhelming majority of the human race. The Outsider is the man who has faced chaos. If he is an abstract philosopher — like Hegel — he will try to demonstrate that chaos is not really chaos, but that underlying it is an order of which we are unaware. If he is an existentialist, he acknowledges that chaos is chaos, a denial of life — or rather, of the conditions under which life are possible. If there is nothing but life and chaos, then life is permanently helpless — as Sartre and Camus think it is. But if a rational relation can somehow exist between them, ultimate pessimism is avoided, as it must be avoided if the Outsider is to live at all. It is this contribution which makes Shaw the key figure of existentialist thought.

The existent individual, as Kierkegaard defines him, is first of all he who is in an infinite relationship with himself and has an infinite interest in himself and his destiny. Secondly, the existent individual always feels himself to be in Becoming, with a task before him;

Jaspers sees the historical meaning of existential philosophy as a struggle to awaken in the individual the possibilities of an authentic and genuine life, in the face of the great modern drift toward a standardized mass society.

Atheistic existentialism, of which I am a representative, declares with greater consistency that if God does not exist there is at least one being whose existence comes before its essence, a being which exists before it can be defined by any conception of it. That being is man....