…we have the division of the spiritual life which has been adopted since the time of the Pseudo-Dionysius into the “purgative” way, the “illuminative” way, and the “unitive” way. St. Thomas well explains the reason for this division when he says: “The first duty which is incumbent on man is to give up sin and resist concupiscence, which are opposed to charity; this belongs to beginners, in whose hearts charity is to be nursed and cherished lest it be corrupted. The second duty of man is to apply his energies chiefly to advance in virtue; this belongs to those who are making progress and who are principally concerned that charity may be increased and strengthened in them. The third endeavor and pursuit of man should be to rest in God and enjoy Him; and this belongs to the perfect who desire to be dissolved and to be with Christ.”

– The Catholic Encyclopedia: ‘State Or Way’, 1913, (as in the Rev. Alban Goodier’s ‘Life That Is Light’ in three volumes ’Purgative’, ‘Illuminative’ and Unitive’, published by P. J. Kenedy & Sons in 1957)