The Marital Act as a Human Act
Selections of Theology for Married Couples
By Diego Velázquez - File:Velazquez-Oriola.jpg, Public Domain, https://commons.wikimedia.org/w/index.php?curid=18895310
Text taken from Sex Ed for Married Catholics: Part 3, Lesson 2 - Introduction to Moral Theology
Learning Objectives
By the end of the lesson, the learner will
Define a human act and distinguish it from an act of man according to St. Thomas Aquinas.
Identify and explain the eight stages of a human act, and how they apply to the marital act.
Analyze the three moral elements of an act (object, intention, and circumstances) and how they determine moral goodness or evil.
Understand how circumstances affect the morality of an act, including cases where they increase, decrease, or change its moral species.
Examine how ignorance influences moral responsibility, distinguishing between invincible, vincible, and affected ignorance.
Explore how fear affects voluntariness and culpability, particularly in marital intimacy.
Apply these moral principles to real-life marital situations, ensuring that moral acts remain free, informed, and virtuous.
Lesson Introduction
In this course, Sex Ed for Married Catholics, we have explored the biological, psychological, and sacramental aspects of human sexuality. We’ve examined the beauty of the marital act, the science of fertility, and the emotional dynamics of intimacy. Now, we turn to an equally essential dimension—moral theology.
Why?
Why does morality matter in marriage? Because love and virtue are inseparable. The Catholic Church teaches that marital intimacy is not just about biology or pleasure—it is a moral act. In this lesson, we will explore what makes an act, a human act, the marital act, and then how to do the marital act in a moral way.
Understanding these moral principles is not about restricting pleasure or imposing rules, but about unfolding the true purpose of marital intimacy—one that reflects both God’s plan and the deepest desires of the human heart.
What is an act?
Human Acts (Actus Humanus):
“Therefore those actions are properly called human which proceed from a deliberate will.” (SmTh, I-II, q. 1, a. 1, resp.).
These acts involve both intellect and will.
They are voluntary, meaning they are known and chosen.
Example: Praying, choosing a career, giving to charity.
Acts of Man (Actus Hominis):
These are acts that happen in a human being but are not deliberate or voluntary.
Example: Breathing, digestion, reflexes.
Thus, for Aquinas, an act is human only if it is voluntary (ex voluntate deliberata), meaning it comes from both reason and will.
Stages of Human Acts
Human Acts, from both reason and will, don’t just happen. We can break these acts down into eight distinct steps, which we may not even realize that we do. Even if they take mere moments, these are the stages that our minds go through with every human act.
Note that when we are talking about the marital act, we are talking about the acts of two people, so their progression through the stages of a human act will not necessarily be on the same timeframe. For example, one may have planned and prepared for a romantic evening weeks in advance, while the other was surprised. For the one this process took weeks, for the other it will take minutes or hours.
First: Apprehension of the End (Apprehensio Simplex)
The intellect first perceives a possible goal or good to be pursued.
Example: A person recognizes that exercising is good for health.
In the Marital Act:
This initial stage is where one or both spouses think about having sex (i.e., it crosses someone's mind). At this point, it is simply recognized as a good to be desired. No choice has been made whether or not to pursue it at this time. This stage can take place weeks or seconds before the completed act. This is the very beginning of the excitement phase of the sexual response cycle.
Second: Desire for the End (Velle - Wish)
The will inclines toward this perceived good as something desirable.
Example: The person feels drawn to the idea of exercising.
In the Marital Act:
This is where attraction and emotional connection deepen into a longing for intimacy. The spouses feel drawn toward each other, experiencing not only physical desire but also the emotional and spiritual pull to unite as one. This stage corresponds to the increasing physiological and psychological anticipation of sexual union, moving beyond passive attraction to an active longing.
Third: Judgment and Deliberation (Intentio Simplex and Consilium)
The intellect considers whether the goal is truly good and deliberates on how to achieve it.
Example: The person weighs the benefits of exercise, different workout options, and possible obstacles.
In the Marital Act:
The spouses assess whether engaging in the marital act at this time aligns with their mutual well-being and responsibilities. They consider factors such as emotional readiness, the wife's fertility cycle, and physical or situational constraints. This stage helps them discern if this is the right moment or if it should be delayed, ensuring that the act will be an expression of love and not one of selfishness or mere physical release.
Fourth: Judgment of the Means (Iudicium)
The intellect decides what means are best suited to achieve the goal.
Example: The person concludes that a morning workout routine is the best approach.
In the Marital Act:
Having determined the appropriate time for intimacy, the couple decides how best to engage in the act in a way that is respectful, loving, and in accordance with their values and Church teaching. This includes considering the needs and desires of both spouses, ensuring mutual consent and pleasure, and fostering a connection that enhances their unity rather than reducing intimacy to mere physical gratification.
Fifth: Election (Electio modi - Choice of Means)
The will chooses the specific means to achieve the goal.
Example: The person chooses running over weightlifting as their preferred workout.
In the Marital Act:
The couple actively chooses how they will engage in the marital act, considering various aspects such as location, timing, ambiance, and means of enhancing intimacy. This includes deciding on elements like whether to engage in foreplay, the setting (e.g., bedroom, shower), the use of lingerie or marital aids, preferred positions, or incorporating music to create a more intimate atmosphere. This stage ensures that their approach to intimacy is both intentional and mutually fulfilling, deepening their connection while respecting the dignity of each spouse.
Sixth: Command of the Will (Imperium)
The will commands the execution of the chosen means.
Example: The person makes a concrete plan to wake up early and go running.
In the Marital Act:
At this stage, the spouses fully consent to the marital act, leading with affection, tenderness, and responsiveness to one another. This is the initiation of physical intimacy or its continuation, but now with the will to follow through to the completed act. This stage is complete when both spouses have implicitly or explicitly consented to the marital act.
In the case of non-consent:
If one spouses does not consent, at least interiorly, to the marital act, then continuing is a violence against them. This then becomes a case of marital rape. Although the marital debt is incurred with the consent given during one’s wedding, this consent must be renewed, at least implicitly, with each marital act. Further, the marital debt does not require consent in all circumstances. Two wrongs don’t make a right: the injustice caused by the violation of the marital debt does not justify the injustice of violation of a spouse’s free will. If one spouse should internally refuse consent, but make no external protest, this is dishonest and creates a moral stumbling block for the other spouse, who will then proceed with the violence in ignorance. The roles of ignorance and fear will be discussed later.
Seventh: Use (Usus)
The intellect and will direct the faculties (body, mind, emotions) toward carrying out the action.
Example: The person physically gets up, puts on running shoes, and goes for a run.
In the Marital Act:
The couple fully engages in the marital act, bringing their bodies, minds, and hearts into complete unity. This is where the sexual response cycle reaches its peak, culminating in the full self-gift of each spouse to the other. This stage covers all activities from foreplay to consummation to aftercare as parts of a whole. Because they are intentionally all means to the same end, they are morally unified. When properly ordered, this time is not only physically pleasurable but also a profound act of love, deepening marital intimacy.
Eighth: Enjoyment (Fruitio or Complaisance)
The will rests in the achievement of the goal and experiences satisfaction or delight in the good attained.
Example: The person feels good after running and enjoys the health benefits.
In the Marital Act:
The marital act reaches its completion, and the spouses rest in the joy, peace, and emotional closeness that result from their union. This stage extends beyond mere physical pleasure, fostering a sense of security, love, and connection. If the act has been entered into with love, respect, and openness to God’s grace, it strengthens both the marital relationship and the spiritual bond between the spouses.
As it Concerns Sexual Satisfaction:
This stage normally begins during the use stage at the point of climax and continues into aftercare with the resolution phase. Note here that I say climax, not orgasm, because one orgasm may not be the “peak.” The true climax is the orgasm after which full sexual release is felt and no further sexual stimulation is needed or desired. In the words of the sexual response cycle, the climax is the orgasm (or end of the plateau) that immediately precedes the resolution phase.
For men, the climax is typically their first and only orgasm of that session.
For women, there is no such thing as typical.
Every woman is different and her needs may change from one day to another.
She may have a strong orgasm and then enter resolution.
She may require multiple orgasms finally reaching the peak and achieving satisfaction.
She may have an extended plateau and then enter the resolution phase without orgasm at all, yet still satisfied.
When we understand that each spouse goes through the same stages of act, but not at the same time, and that the fruitio is the true completion of a human act, we can start to understand how denying or neglecting that fruitio is an injustice.
“When we understand that each spouse goes through the same stages of act, but not at the same time, and that the fruitio is the true completion of a human act, we can start to understand how denying or neglecting that fruitio is an injustice.”
The Elements of A Moral Act
St. Thomas Aquinas identifies three essential elements of a moral act in the Summa Theologiae (I-II, q. 18). These elements determine whether a human act is morally good or evil.
Object - What is done
Intention - Why it is done
Circumstances - External factors (who, where, when, etc.)
1. The Object (Finis Operis – The Act Itself)
The object is the specific action being performed, considered in itself.
It gives the act its moral species (i.e., whether it is intrinsically good or evil).
Some objects are always good (e.g., almsgiving), and some are always evil (e.g., murder, adultery).
Aquinas states:
“And just as a natural thing has its species from its form, so an action has its species from its object, as movement from its term.” (Summa Theologiae, I-II, q. 18, a. 2)
Examples:
Telling the truth is inherently good.
Lying is inherently evil.
2. The End (Finis Operantis – The Intention)
The end or intention is the goal or purpose for which the act is done.
The same act can be good or evil depending on the intention.
A good object can be corrupted by a bad intention.
Note: The intention is the first circumstance.
Aquinas states:
“Although it is accidental to the external action to be ordained to some particular end, it is not accidental to the interior act of the will, which act is compared to the external act, as form to matter.” (Summa Theologiae, I-II, q. 18, a. 4)
Examples:
Giving money to the poor (good act) but doing it for human praise (bad intention).
Fasting for spiritual discipline (good act and intention) vs. fasting to show off (good act, bad intention).
3. The Circumstances (Conditions Surrounding the Act)
Circumstances modify the gravity of an act, but do not usually change its moral species.
They answer who, where, when, how, and by what means.
Some circumstances can make an act more or less praiseworthy or blameworthy.
Aquinas states:
“A circumstance, so long as it is but a circumstance, does not specify an action, since thus it is a mere accident: but when it becomes a principal condition of the object, then it does specify the action.” (Summa Theologiae, I-II, q. 18, a. 10, r. 2)
Increasing the Gravity of an Act
Circumstances can intensify the moral weight of an act, making it more serious.
Example: Stealing from a Church vs. Stealing from a Merchant
Stealing is always sinful because it involves taking what does not belong to you (bad object).
However, stealing from a sacred place (like a church) worsens the sin because it adds sacrilege as a circumstance.
Aquinas states: “Hence according to the present judgment the pain of death is not inflicted for theft which does not inflict an irreparable harm, except when it is aggravated by some grave circumstance, as in the case of sacrilege which is the theft of a sacred thing…” (Summa Theologiae, II-II, q. 66, a. 6, ad 2)
Decreasing the Gravity of an Act
Certain circumstances can lessen the moral culpability of an act.
Example: Lying to Save a Life
Lying is intrinsically evil because it contradicts truth, but lying to protect someone from unjust murder may be less sinful.
Aquinas distinguishes between lying for vanity vs. lying to prevent grave harm.
The circumstance of saving an innocent life does not make lying good but mitigates its gravity.
Aquinas states: “But if the end intended be not contrary to charity, neither will the lie, considered under this aspect, be a mortal sin, as in the case of a jocose lie, where some little pleasure is intended, or in an officious lie, where the good also of one’s neighbor is intended.” (Summa Theologiae, II-II, q. 110, a. 4, resp.)
Changing the Moral Species of an Act
Some circumstances change an act from one moral species to another.
Example: Killing in Self-Defense vs. Murder
Murder (deliberate killing of an innocent person) is always sinful.
Killing in self-defense, however, can be morally permissible if:
The intent is to preserve life (one’s own or one’s family/friends), not to kill.
The force used is proportional (deadly force to deadly force).
The circumstance of self-defense shifts the act’s moral species from murder (unjust killing) to legitimate defense.
Aquinas states: “Now moral acts take their species according to what is intended, and not according to what is beside the intention, since this is accidental as explained above (Q. 43, A. 3; I-II, Q. 12, A. 1).” (Summa Theologiae, II-II, q. 64, a. 7)
Moral Evaluation Based on These Elements
Aquinas holds that for an act to be morally good, all three elements must be good:
The object must be good.
The intention must be good.
The circumstances must not render the act evil.
If any one of these is bad, the entire act is morally flawed:
A bad object always makes the act evil (e.g., contraception).
A bad intention corrupts an otherwise good act (e.g., sex to exert power over one’s spouse).
Bad circumstances can increase guilt (e.g., sex without taking precautions for modesty).
Aquinas summarizes this principle: “An action is not good simply, unless it is good in all those ways: since evil results from any single defect, but good from the complete cause, as Dionysius says (Div. Nom. iv).” (Summa Theologiae, I-II, q. 18, a. 4, ad 4)
Ignorance and Fear
Not all moral acts are equally voluntary.
Ignorance and fear can affect responsibility and culpability.
Ignorance and Moral Responsibility
Moral acts require knowledge: One must know an act’s moral significance to be fully responsible.
Ignorance can reduce or eliminate guilt, depending on whether it is avoidable or unavoidable.
Types of ignorance (Summa Theologiae, I-II, q. 76):
Invincible ignorance – Cannot be overcome; removes culpability.
Vincible ignorance – Could be overcome with effort; does not excuse sin.
Affected ignorance – Deliberate ignorance to avoid responsibility; increases culpability.
Examples:
Invincible Ignorance: A newly converted Catholic who unknowingly violates a moral teaching is not culpable.
Vincible Ignorance: A Catholic who refuses to learn Church teachings on contraception is still culpable.
Affected Ignorance: A spouse choosing not to research marital ethics to justify selfish behavior.
A Crisis of Our Times
In my opinion, there are many Catholics who, despite their best efforts, fall into invincible ignorance when it comes to marital intimacy because of the sparsity of reliable information on the matter.
Sadly, many priest, deacons, and religious are not sufficiently formed in this area to address the concerns of the faithful.
CatholicIntimacy.com and this course were conceived to rectify that problem.
When in doubt, ask.
Fear’s Influence on Voluntariness
Fear does not remove voluntariness but can lessen it (ST, I-II, q. 6, a. 6).
A person acting under grave fear may be less responsible.
However, fear never justifies an intrinsically evil act.
How Fear Affects Moral Responsibility
Overwhelming Fear (Grave Fear): Reduces culpability but does not eliminate responsibility (e.g., feigning consent under threat of rape, instead of active resistance).
Moderate Fear: Still voluntary but may influence the act’s merit (e.g., engaging in intimacy due to emotional pressure).
Fear as an Excuse vs. Justification: One cannot justify evil due to fear, but it may mitigate guilt.
Fear and the Marital Act
Fear should never be a factor in the marital act.
Authentic intimacy is freely given, not coerced (CCC 2364-2365).
Examples:
A spouse fears emotional withdrawal if they refuse sex → less free but still voluntary.
A spouse engages in intimacy under physical threat → invalidates consent.
The marital act must be free from fear for true love and unity to be present.
Conclusion
Understanding human acts is very helpful for living a virtuous moral life. By analyzing how moral acts are structured, how moral elements shape their goodness, and how external factors like ignorance and fear influence responsibility, we become better equipped to make choices that are truly free, responsible, and loving.
Key Takeaways:
Moral acts must be voluntary, with knowledge and freedom.
The elements of a moral act are object, intention, and circumstances.
Ignorance affects culpability—invincible ignorance excuses, vincible does not.
Fear may lessen voluntariness but does not justify evil.
In marriage, intimacy must always be freely chosen, never coerced.
This section of Sex Ed for Married Catholics begins with the Sacramental Theology of Marriage, highlighting its divine institution, ends, and graces. It then explores moral theology, covering the marital act, marital debt, distinctions between complete and incomplete acts, common questions on intimacy, and sins against marital chastity, guiding couples toward virtuous and holy marital love. (This course is still in production, but you can still register and watch new lessons as they come out.)
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