Eliphas Levi, the first of the modern "ceremonial magicians" and predecessor to the "Golden Dawn" defined the Great Work thus:
The magnum opus is pre-eminently the creation of man by himself, that is, the full and complete conquest which he can make of his faculties and his future; it is pre-eminently the perfect emancipation of his will.
The modern incarnation of the Golden Dawn defines the Great Work as "a term borrowed from alchemy's magnum opus. Refers to the path of human spiritual evolution, growth and illumination, which is the goal of ceremonial magic."