How Do We Know What’s Right and Wrong? Deontology vs. Consequentialism

 In Articles, Ethics, Morality, Philosophy

In 2006, the show Dexter aired. It was a hit. I’ve never watched the show, but several of my friends loved it. The show paves the way for an interesting ethical debate.

If you’re not familiar with the show’s premise, the main character is Dexter Morgan. He’s a forensic technician for the Miami Police Department, specializing in bloodstain pattern analysis. Dexter seems like a good guy, but he has a secret. He’s a sociopath and a serial killer. But there’s a catch. He only kills other killers. He’s a vigilante. He supposedly only kills those that deserve to die.

Some viewers saw Dexter as a hero, the man bringing justice to those who deserve punishment. But there’s an obvious dilemma here. One friend of mine admitted, “I know that Dexter is wrong. His actions are bad, obviously. But when I was watching the show, I found myself rooting for him. There were a few times he almost got caught, and I was nervous for him. Isn’t that terrible? I was rooting for the monster.”

Question: Is Dexter a hero or villain?

Answer: It depends on your approach to ethics.


Ethics Defined

What is ethics? Ethics is the branch of philosophy that seeks to determine the difference between right and wrong or the difference between good and evil. The study of ethics often seeks to understand which human behaviors are immoral and which human behaviors are moral. Ethicists often seek to give us frameworks or rubrics that we can use to determine whether a particular human behavior is good or bad.

Many different people have different systems for how they form their ethics. There are multiple categories of ethics and many different approaches. However, the two big buckets of ethical theories that are most commonly discussed by philosophers are aretaic theories of ethics and deontic theories of ethics.[1]


Aretaic vs. Deontic

Aretaic theories of ethics seek to determine whether a person or thing is good or bad. Aretaic theories mostly deal with this question: What is the substance of goodness, truth, and beauty? Aretaic theories of ethics seek to determine whether the essence of a person or thing embodies goodness and virtue.

Aretaic theories are certainly worthy of discussion, but this article won’t deal much with aretaic theories. This article will focus on deontic theories of ethics.

Deontic theories of ethics attempt to define how people should behave and how people should not behave.

Deontic ethical theories are less concerned with the inward essence of a person, instead, deontic theories of ethics are concerned with a person’s outward behavior—their choices, not their inward constitution.

It could be said that aretaic ethical questions deal with the goodness (or lack thereof) of a person’s soul. Deontic ethical questions deal with the goodness of a person’s actions.

A study of deontic theories of ethics asks these types of questions:

  • Which actions are moral and which are immoral?
  • What behaviors are right and which ones are wrong?
  • What choices are good and which ones are bad?
  • What’s an evil decision and what’s a decision worthy of praise?

There are two primary forms of deontic theories of ethics: deontology and consequentialism. Both of these theories tend to deal with questions related to duty, obligation, rights, and moral choices.[2]


Deontology Unpacked

What is deontology? Deontology is the belief that every action should be judged on the merit or quality of the action itself, regardless of the results or consequences. Proponents of deontology assert that an action itself can be wrong and immoral, even if it leads to positive or good benefits, and an action itself can be good and moral, even if it leads to negative consequences.

The word deontology comes from the Greek root word δέον (“deon”), meaning “rule” or “duty.”[3] In deontology, a person’s actions are judged as right or wrong based on the actions themselves, regardless of the outcomes or consequences. The actions are either right or wrong based on whether they are consistent with certain moral duties.[4]

Deontology is a deontic ethical theory because it seeks to measure a person’s behavior and outward actions—deontology does not necessarily seek to measure a person’s inward constitution or soul. And the behavior itself is being measured, regardless of what might happen in the wake of that behavior.

Proponents of deontology are not using the results of any human choices to determine if those choices are moral or immoral.

This is where were we begin to wrestle with the common societal question: “Do the ends justify the means?”

Is it okay to steal or kill or defraud if it leads to some greater good? The strict deontologist says, “No, the ends do not justify the means.” The strict deontologist says it is always wrong, no matter what the reason, and no matter what the results. If something is wrong, then it’s wrong, no matter the outcomes, benefits, or consequences.

Under the overarching umbrella of deontological theories, actions are quite plainly either moral or immoral, it’s black or white. The circumstances, motivations, or beneficial outcome do not redeem an immoral choice.[5]

For example, robbing a bank is wrong and immoral, even if the money that is stolen is later given to a poor starving family in need. In this approach, some actions are always considered morally prohibited.[6]

Deontological theories hold humans accountable for immoral choices, even if those choices may have led to some good result. The strict deontologist would condemn Dexter for his actions, no matter what the circumstances or motivation.


Divine Command Theory

There are multiple variations of deontology. One very common deontological system is called Divine Command Theory. This system emphasizes that God establishes objective standards of right and wrong.

In this system, the moral status of an action depends on whether it functions according to the rules commanded by the divine.[7] In other words, something is wrong if God says it’s wrong and something is good if God says it’s good.

Most contemporary evangelical Christians would profess to adhere to some variation of Divine Command Theory, with the Bible being the source of God’s edicts and instructions.

Of course, different groups of Christians have differing views of the Bible, therefore how tight they hold to this way of governing their approach to ethics may vary.

The historic Christian position has been that the Bible is the inspired and infallible Word of God. The Bible cannot ever fail and it is the ultimate source of truth. Therefore, many Christians throughout history have advocated that societies embrace the Bible as the primary source for morality.

Theologian Millard Erickson says, “There must be some basis for ethics and morality… [therefore there must be] a God who establishes and supports values, and who rewards good and punishes evil. Thus, the moral order… requires the existence of God.”[8]

Erickson later writes that the “true and unadulterated” life of Jesus—his conduct, ethics, and lifestyle—is “the standard by which we are to be measured.”[9]


Deontology By Intuition

In contrast to Divine Command Theory, there are some deontologists that claim that morality is known by humans by intuition or personal reflection. They would still subscribe to the basic premise of deontology.

However, these types of deontologists would argue that we do not need God to tell us what is right and wrong because humans already know it, intuitively, or because humans can reason their way toward right morality. Some of these types of deontologists have appealed to the concept of natural law.

My study of both the Scriptures and human psychology leads me to pushback on intuition as a reliable primary means of determining morality. Humans tend to be overly emotional, fickle, and terribly subjective. For this reason, I reject the notion that we can just intuitively know right from wrong in all situations.

There may be times when humans do know right from wrong without the Bible specifically telling them. Yes, that might be true at times—mostly because humans are made in the image of God and therefore some elements of the morality God remain. So yes, there are plenty of moments when people do indeed intuitively know that a certain action is right or that a certain action is wrong.

However, human sin has impacted all of us and maligned our ability to see clearly. The Bible says, “There is a way that seems right to a man, but its end is the way to death” (Prov. 14:12).

Relying on human intuition is a terribly unreliable way to approach ethics long-term.


Consequentialism Unpacked

What is consequentialism? Consequentialism is the belief that every action should be judged based primarily on the results or consequences of the action. Proponents of consequentialism assert that an action itself is good and moral if it leads to positive or good benefits, and the action is bad and immoral if it leads to negative consequences.

Consequentialist theories are sometimes called teleological theories, from the Greek word τέλος (telos), or end.[10] This school of thought emphasizes that the best actions are those which produce the best results.[11] In consequentialism, a person’s actions are primarily judged based on the results or outcomes of those actions.

There are multiple variations of consequentialism. They are not all equal. But generally speaking, consequentialism is often seen as the opposite of deontology.

Consequentialism is also a deontic ethical theory (like deontology) because it seeks to measure a person’s behavior and outward actions—it does not attempt to measure a person’s inward constitution or soul. However, unlike deontology, consequentialism measures behaviors in light of what might have happened in the wake of those behaviors.

The consequentialist might argue that Dexter’s killings are justified because the result is less killers on the streets. In that instance, the strict consequentialist might say that the ends justify the means.

There are many people in contemporary western societies that have endorsed or embraced some variation of consequentialism. However, very few people could be fairly labeled as being strict consequentialists. Almost everyone seems to have some category of behaviors that they would say are indeed immoral, no matter what benefits may come from those behaviors. But each person seems to draw the lines at different places, for different reasons. One common criticism is that the entire consequentialist framework seems terribly arbitrary.

Another common criticism of consequentialism is that it can lead to “justifying any number of behaviors, including the oppression and exploitation of others, so long as the outcomes are good enough for a large enough group of people.”[12] This leads to a philosophy that upholds ends above all else, allowing an agent to make use of ethically questionable means in the process.

Additionally, making ethical decisions becomes challenging when a person attempts to compare two beneficial outcomes: How would they choose the ‘better’ option?[13] This renders consequentialism as potentially being arbitrary or inconsistent or both.


Utilitarianism Unpacked

There are different types and shades of consequentialism. Most of the distinctions between the different types of consequentialism come down to which consequences count toward determining whether or not an action was good.

Variations of consequentialism have existed since the days of antiquity. However, when people use the term consequentialism now, they are most often referring to a modern theory: classic utilitarianism.[14]

Classic utilitarianism defines ethical choices as those which bring about happiness or pleasure-causing outcomes. Often, the claims of this system are summarized in the slogan that “an act is right if, and only if, it increases the net good overall.”[15]

One of the most prominent thinkers associated with classic utilitarianism is the English philosopher Jeremy Bentham (1748-1832). He emphasized the importance of each action seeking to maximize pleasure and to minimize pain, both for the individual and for the other persons affected.

In Bentham’s approach, a person’s choices could be considered good and moral if they brought about more pleasure and more happiness for more people. Bentham developed a calculator known as the felicific calculus, that determined the degree to which an act causes either pleasure or pain. To come to a solution, Bentham’s model evaluated several characteristics of an act, such as intensity, duration, and remoteness.[16]

One of Bentham’s students, John Stuart Mill (1806-1873), disagreed with his mentor. While Mill believed that people should make choices based upon the best outcomes, he did not prioritize pleasure as the highest good as his mentor had done.

Mill understood that encountering some of the best experiences in life will require people to undergo pain at times; thus, he instead measured the value of an action in terms of harms versus benefits.[17] This variation of consequentialism is known as rule utilitarianism.

Utilitarianism has become the most popular variation of consequentialism in the modern western world. This ideology tends to govern the ethics of many Americans.

While there may be moments or circumstances in our lives when utilitarianism seems appropriate, it’s very important to note that the essence of utilitarianism is at odds with the Christian worldview.


Money for Sex: One Man’s Proposition

As we wrap-up this article, let’s end with one more analogy that should be helpful to illustrate the key distinction between deontology and consequentialism.

This analogy comes from a well-known provocative story about a man offering a women money for sex. There are several different variations of this story floating around the internet.[18] Here’s my paraphrase of the story.

There was a man who asked a woman if she would be willing to have sex with him for a large sum of money. He says something like, “I’m a multi-millionaire. I’ll give you a million dollars for sex.”

At first, she’s angered and offended that the man would ever make such an offer. But, after thinking it over for a while, she agrees to do it. She says yes to his proposition. Besides, it’s a lot of money, right? They then have a quality conversation.

Later in the conversation, the man changes the offer. He says something like, “Listen, I’ve changed my mind. Instead of a million bucks, how about… hmmm… $20.”

The woman is outraged at the paltry offer. She replies, “What kind of woman do you think I am?”

He replies, “Well, I think we’ve already established what kind of women you are. Now we’re just haggling over the price.”



This story about the man offering money for sex illustrates how the morality of humans can sometimes shift, depending on the situation they find themselves in.

The woman in the story was outraged at the smaller amount, because she did not consider the ramifications (or the benefits) of having sex with the man as being valuable enough. However, she had been willing to go through with it or the larger amount. Apparently, the benefit was simply too great to pass up when the price tag was $1million.

Is having sex for money always immoral?

Should the amount of money matter?

This highlights the difference between deontology and consequentialism.

The strict deontologists would say that Dexter’s actions in the show were wrong, no matter the benefit. They would also say that sex for money is immoral, no matter the price tag or benefits.

The strict consequentialists could argue that Dexter’s actions are good because of the benefit to society. They’d also likely say that sex for money is not necessarily inherently immoral. In consequentialism, the benefits could indeed dictate the morality. The ends justify the means.

Understanding the differences between deontology and consequentialism is essential when we begin to engage in contemporary controversial debates, especially debates about topics such as abortion and other life-related issues.


Featured image of the television character ‘Dexter’ taken by Randy Tepper of Showtime, courtesy of Entertainment Weekly.



  1. For additional research see, “Deontic vs. Aretaic Ethical Theories,” YouTube video,
  2. Dwight Boyd, “The Moralberry Pie: Some Basic Concepts,” Theory Into Practice 16:2 (1977): 67-72,
  3. One Minute Apologist, “611. What is Deontological Ethics?” YouTube video,
  4. The Ethics Centre, “Deontology,” YouTube video,
  5., “What is Deontology?” YouTube video,
  6. Larry Alexander and Michael Moore, “Deontological Ethics,” The Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta, March 12, 2019,
  7. For more information on divine command theory, see John E. Hare, “Divine Command Theory and Moral Obligation,” Oxford University Press Blog, February 13, 2016,
  8. Millard Erickson, Christian Theology. 3rd edition. (Grand Rapids: Baker Academic, 2013), 131.
  9. Ibid, 657.
  10. James Fieser, “Ethics,” Internet Encyclopedia of Philosophy,
  11. The Ethics Centre, “Ethics Explainer: Consequentialism,” February 15, 2016,
  12. Ibid.
  13. The Ethics Centre, “Ethics Explainer: What Is Deontology?,” February 17, 2016,
  14. Walter Sinnott-Armstrong, “Consequentialism,” The Stanford Encyclopedia of Philosophy, edited Edward N. Zalta, Summer 2019,
  15. Ibid.
  16. James E. Crimmins, “Jeremy Bentham,” The Stanford Encyclopedia of Philosophy, edited by Edward N. Zalta, Summer 2020,
  17. The Ethics Centre, “Consequentialism.”
  18. Quote Investigator, “Now We’re Just Haggling Over the Price,” March 7, 2012,