By their capacity for the immortal deed, by their ability to leave non-perishable traces behind, men, their individual mortality notwithstanding, attain an immortality of their own and prove themselves to be of a “divine” nature. The task and potential greatness of mortals lie in their ability to produce things – works and deeds and words – which would deserve to be and, at least to a degree, are at home in everlastingness, so that through them mortals could find their place in a cosmos where everything is immortal except themselves. This is mortality: to move along a rectilinear line in a universe where everything, if it moves at all, moves in a cyclical order. This individual life is distinguished from all other things by the rectilinear course of its movement, which, so to speak, cuts through the circular movement of biological life. The mortality of men lies in the fact that individual life, with a recognizable life-story from birth to death, rises out of biological life.

Men are “the mortals”, the only mortal things in existence, because unlike animals they do not exist only as members of a species whose immortal life is guaranteed through procreation. Imbedded in a cosmos where everything was immortal, mortality became the hallmark of human existence. Chicago and London: The University of Chicago Press.

The Human Condition by Hannah Arendt