The Spiritual Exercises is not a book to be read straight through; it is a director's manual for a roughly four-week retreat. Ignatius opens with twenty Annotations that explain how to give and receive the Exercises, how to adjust them to the strength and circumstances of each person, and how the one helping should stay out of the way so that the retreatant deals directly with God.
The whole structure rests on the Principle and Foundation. A person is created to praise, reverence, and serve God and so to be saved, and all other things are means to that end. From this Ignatius draws the discipline of indifference: not coldness, but a refusal to let health, riches, honor, or long life decide for you in advance, choosing instead only what most leads to the end for which you were made.
The First Week turns to sin and mercy. Alongside its meditations Ignatius installs two practical engines that run throughout: the particular examen, which targets a single fault hour by hour, and the general examen of conscience, which sorts the day's thoughts, words, and deeds. Here he also distinguishes the kinds of thoughts in a person, those that are one's own and those that come from the good or the bad spirit.
The Second, Third, and Fourth Weeks contemplate the life, passion, and risen life of Christ. Set pieces frame the choice the retreat is building toward: the Call of the Temporal King, which asks whether you will labor with Christ; the Two Standards, which contrasts the way of riches, honor, and pride with the way of poverty, contempt, and humility; and the meditation on three classes and three ways of being humble, all sharpening how a person makes a sound election, or choice of life.
Two further sets of material carry much of the book's lasting influence. The rules for the discernment of spirits teach a person to notice consolation and desolation, to hold firm in resolutions when desolate, to expose the enemy's secrecy, and to test even good-seeming impulses by where they end. The Contemplation to Gain Love closes the retreat by recalling all that God has given and answering with total self-offering, on the conviction that love is shown more in deeds than in words.