Existence, the translation of the Latin word 'existentia,' etymologically corresponds to 'being' in ancient Greek, that is, a concept denoting the reality of being. However, the metaphysical term 'existence' became closely associated with human self-explanation through the influence of existential philosophy.
Søren Kierkegaard (1813–1855), known as the precursor of modern existential philosophy, defines humans as existents, understood not as defined by an essential 'what,' but as 'how'—freely and responsibly actualizing themselves as a subject. In other words, for humans, what matters is not 'what one is,' but 'how one is.'In this regard, Kierkegaard argues that humans, as spirits, realize themselves as existence only through a synthesis that relates the infinite and the finite, eternity and time, freedom and necessity, and soul and body to themselves. Kierkegaard calls the highest passion of subjective human inwardness toward truth: 'faith'.
Karl Jaspers (1883–1969) understands existence as a 'possibility of being' that realizes the true self through acts of self-choice and self-determination within historical circumstances. For him, existence is the deepest, most profound concept. Existence is unique and cannot be substituted; it reveals the self in a transcendent way concerning one's possibility of being, particularly within situations of limitation. This refers to humans fundamentally striving to transcend their own limits (suffering, struggle, guilt, death)
Jaspers also identifies freedom, reason, and (existential) communication as conditions for becoming an actual existent. As a fundamentally free being, a human can relate to the transcendent 'One' (the ultimate and absolute truth that unifies everything) and move beyond a defined world toward the realization of true existential potential.
Jaspers called this free relationship with the transcendent being ‘philosophical faith’ arising from the self-assurance of existence. Unlike revealed faith, it is based solely on ‘reason’. For reason is the source of open transcendence, extending infinitely without self-constraint. That is, reason can be called ‘the source of the impulse that infinitely pursues unity toward the One’ and ‘the space of infinite communication’. Within this unrestricted space of reason, existence engages in existential communication with the transcendent being to become its true self. As an existence, humanity is never a predetermined ‘being that is’, but rather a ‘being that becomes,’ advancing toward its potential existence. This is why we constantly strive to become ourselves.
