Man is a rope, fastened between animal and Superman — a rope over an abyss. A dangerous going-across, a dangerous wayfaring, a dangerous looking-back, a dangerous shuddering and staying-still.
Nietzsche defines the rope as the primary symbol of human transitional existence, a tensioned span between animality and the ideal of the Superman stretched over existential nothingness.
, Thus Spoke Zarathustra, 1883thesis