The existentialist insists that, for human beings, existence precedes essence. The essence of an object is its function. For example, the essence of a chair is that it supports a seated person. As a chair is manufactured to fulfill this function, its essence precedes its existence: The manufacturer determines the function of the chair before the chair is brought into existence by being manufactured. Humans come into existence without a predetermined function, or essence, which is to say there is no manufacturer of humans. Each individual human self, or subject, must recognize that he or she exists and then determine his or her essence. Commitment to one’s essence constitutes authenticity. One’s essence may be whatever one chooses, within one’s capacities: medical practice, criminality, aspiration to sovereignty, plumbing, teaching, meditation, aspiration to spiritual fulfillment, or whatever one may wish as a basis for meaning in life. To choose religion, as Søren Kierkegaard did, is to want something beyond existence and to commit one’s self to the quest for faith in that something, faith amounting to a subjective experience of that something, which may be called God. The religious existentialist begins with existence and then posits God as, not pre-existential, but extra- or supraexistential. The atheistic existentialist seeks only to make the best of existence and to posit nothing beyond existence.
The atheistic and the religious existentialist accept responsibility for existing. Neither blames God or parents or social conditions for her or his situation. The existentialist accepts the datum that he or she has been thrown into existence. Martin Heidegger calls this having-been-thrown-into-existence Geworfenheit (thrownness). The existentialist is not concerned with the thrower or the whence-thrown, only with the thrownness. As an atheist, one seeks to direct one’s thrownness, for which one is responsible, since it is one’s own, toward one’s choice of action, to which one attaches responsibility. As a religious existentialist, one responsibly directs one’s thrownness “toward God” (Kierkegaard’s ad deum), with the understanding that God is the end, not the agent, of the direction.