Ergon, in alchemy, was a term designating the right eye of the soul, which was turned toward eternity. This was opposed to the left eye of the soul, parergon, which was directed toward time.
Here is seen the religious aspect of alchemy, left toward the sinister and right toward the divine. After failing in purifying metals into gold alchemy tried purifying man.
A.G.H
Source:
Drury, Nevil. The Watkins Dictionary of Magic. London. Watkins Publishing. 2005. p. 93