Calming the appetites
Most people in the post-modern world have an understanding of human psychology that is largely formed by Sigmund Freud and Carl Jung. Freud was a militant atheist, and Jung was probably a pantheist to the extent he had a spiritual life. They ended up as rivals, advancing somewhat different models of the human person, but with the main elements in common.
According to Freud and Jung, each person has a consciousness of self, referred to as the ego or the persona, which is known to the person and to the rest of the world. Also within each person is an unconscious or shadow component, known to a much lesser degree by the person, if known at all. Conflicts arise between the conscious and unconscious parts of the self, producing psychological disorders.
It is perhaps fair to say that these models are primarily useful in diagnosing and treating disorders. They don't tell us how to become holy. For that, we need a different model.
St. John of the Cross was trained in Thomistic philosophy and theology at the University of Salamanca, as part of his formation for religious life. He was a brilliant student, which led him to the priesthood and then to the Carmelite order, after St. Teresa of Avila recognized his learning and holiness of life. St. John presents us with a model of the person that is far superior to the modern secular model. Rather than mechanistic and oriented to dysfunctions, the Thomistic model is humane and intended to aid sanctity. Learning this psychological structure and the associated terminology is essential to understand the writings of St. John of the Cross.
First, the soul is more than just the part of us that goes to heaven, purgatory, or hell when we die. It is the internal principle by which a person thinks, feels, and acts, and which animates our bodies. In the past, when a ship sank, it was common to speak of the number of souls lost. That is the sense in which St. John uses the term soul (alma in Spanish), the whole of the person united to a body.
The soul in a sense operates through faculties, which are the higher powers of the soul, consisting of memory, understanding, and will. Each faculty is created to give expression to one of the spiritual virtues: the purpose of the memory is to animate the virtue of hope; the purpose of the understanding or intellect is to subserve and express the virtue of faith; and the will is meant for only one end, to love as Christ Himself loves. The holy person is the one whose memory, understanding, and will run true with each corresponding virtue.
The soul also features a variety of appetites, which are inclinations or tendencies to seek certain ends. The sensible appetites involve matters, as the name suggests, that are perceptible by the senses. These include both the physical senses (taste, touch, smell, sight, hearing) which seek concrete goods, and the rational senses, which look to the good in the abstract.
In Scholastic philosophy, the sensible appetites are further divided into the concupiscible and the irascible appetites. St. John does not make much of this distinction, focusing instead on the appetites in aggregate. They are the source of the attachments that so hinder a soul's progression in prayer. He uses the terms "appetite" and "desire" somewhat interchangeably, and he counsels that appetites are directed towards everything attractive to the senses, from tangible goods such as food, shelter, and companionship, to spiritual and emotional gratifications such as self-satisfaction with one's penitential practices, knowledge of superiority over rivals, and consolations in prayer.
Immediately we can see that this model is far more detailed and therefore more useful than the mere distinction between conscious and unconscious elements. For example, in the properly ordered soul, the intellect or reason exercises authority over the will and restrains its often disordered desires. The post-modern secular person is more likely to invert this authority and allow the will to reign, making the intellect a mere servant assigned with concocting intelligent-sounding rationalizations for whatever outrages and depravities preoccupy the unrestrained desires. A glance at most university curriculums confirms this.
For St. John of the Cross, calming the appetites is the primary purification that must take place in the night of sense. A sincere and sustained effort is required; the dark night is not an event or a moment of passage. It is a process that may take many months or years. Ultimately it will be completed only by God, through the passive night of sense. The outcome is the clarification and freedom of the soul, attended by the fruits of the Holy Spirit: Love, joy, peace, patience, kindness, generosity, faithfulness, gentleness, and self-control. Gal. 5:22-23. No wonder the whole world admires living saints! We should long to be counted among them.