“What Ignatius strove to achieve was simply to expose to the bright light of consciousness the laws of the soul which determine the ‘voluntary’ actions of man.
The basic law of all human activity seemed to him connected with the observation that every act is preceded by a decision. … So he tried to trace the mechanism by which such decisions are determined. He found that discrimination on the basis of reason is not enough. Reason always calls in the emotions for advice. But the emotions are subject to man’s imagination, which must therefore be recognized as an indispensable link in the dynamic give and take of mind and soul. It follows then that the will, if it wants to control man’s reactions, his behavior and conduct, must make itself master not only of man’s reason and emotions but also of his imagination.
Indeed, only a drill officer with a profound faith in the omnipotence of discipline could hit upon the idea that the soul, exactly like the body, can be forced by an exertion of one’s will to unfold all its potentialities.
As soon as Ignatius had made this discovery, he began to drill his reason, his emotions, and his imagination until all three were subject to his will. In the end he was able to control his onetime unbridled imagination as completely as his feelings and thoughts.” – p. 284-285, Saints That Moved the World by Rene Fulop-Miller
“Ignatius avails himself, in especial, of the power of the imagination; he tries to awaken in his pupils quite definite pictorial representations, all with the object of intensifying the power of distinguishing between right and wrong conduct. … It is through images that Ignatius strives to assist mankind towards perfection; for every day and for every hour of the day the Exercises prescribe exactly what representations to exercitant has to evoke, and of what aids to this end he as to make use. … The exercises of Ignatius is acclaimed to this day  as a psychological masterpiece.” – The Power and Secret of the Jesuits by Rene Fulop-Miller
For more information on the Renaissance and its importance in modern esoteric practices, see: Drawing Down the Life of Heaven – An Introduction to Renaissance Magic
Rosicrucianism for the New Millennium – 400th Anniversary Edition