The Fifth element, there are all the materials that the greeks would pronounce to what fill up the universe, what fills up the vacuum of space.
68% of the vacuum in space is made up of dark energy. The energy that globally effects the entire universe. The energy that accelerates the expansion of the universe.
In the 14th century Ramon Lull developped the theory that there is to little of this fifth element on Earth. The element better known as Quintessence would be researched for healing properties. The quality of the substance would cure any impurities in oneself through consuming it.
In Hesiod's Theogony, Aether (Light), was the son of Erebus (Darkness) and Nyx (Night) and the brother of Hermena (Day)