The Calculus of Happiness: the Legacy of Utilitarianism

Imagine you’re standing on a footbridge overlooking a railway track, and you see a trolley heading towards five workers who are tied to the tracks. You have a lever that can switch the trolley to a different track where only one worker is tied up. Would you pull the lever and sacrifice one life to save five?

This thought experiment highlights the key principle of utilitarianism – the greatest happiness for the greatest number of people. 

It is a moral philosophy that holds that the best action is the one that maximises overall well-being, used to guide decision-making in politics, economics, and social policy, with the goal to create the greatest overall good for society.

It’s a simple yet powerful idea that has sparked intense debates and discussions for centuries, and it’s still relevant today as we navigate complex ethical dilemmas in our rapidly changing world.

i. Utility and the Greatest Happiness Principle

The greatest happiness principle, also known as utility, is an idea that says we should do things that make most people happy. First published by Jeremy Bentham in 1789, the idea is used to make choices about how to make society better. The principle is the foundation of utilitarianism. Taking inspiration from Epicurean philosophy, Bentham and other proponents of this principle believed that happiness or pleasure is the ultimate goal of human action, being the only thing that is good for its own sake. Actions and policies should be evaluated based on their ability to maximise happiness and minimise pain.

To apply the greatest happiness principle, we consider different options and think about their effect. Then we pick the one that will make the most people happy overall, in the long run, and that the benefits are distributed fairly.

Here are some ways to apply this principle:

  • By identifying the goals of the decision or action, we can consider which option is most likely to achieve those goals.
  • We should assess the potential impact of different options on different groups of people, in an attempt to minimise any negative consequences. Seeking input and feedback from those affected by the decision could be part of this assessment.
  • We should also consider long-term and short-term effects, as well as potential trade-offs.
  • Finally, we should continuously monitor and evaluate the decision or action, making sure that it continues to promote the greatest happiness for the greatest number of people.

ii. Act and Rule Utilitarianism


Act utilitarianism and rule utilitarianism are two different approaches to this philosophy. Both approaches share the same goal of promoting the greatest overall well-being, but they differ in how they evaluate the moral value of actions and rules.

Act utilitarianism, also known as “classical utilitarianism”, was first articulated by Jeremy Bentham. It is an approach that focuses on the consequences of individual actions. According to act utilitarianism, an action is morally right if and only if it leads to the greatest overall wellbeing. Under this approach, the moral value of an action is determined by its actual consequences.

Bentham proposed a method to try and measure the utility of actions: what he called the hedonic calculus. It consists of seven factors that should be taken into account.

  1. Intensity, that is, how strong or powerful the pleasure or happiness is.
  2. Duration, that is, how long the pleasure lasts.
  3. Certainty, that is, how sure we are that the pleasure will happen.
  4. Propinquity or proximity, that is, how close in time the pleasure or happiness is.
  5. Fertility, that is, how likely the pleasure or happiness is to lead to other pleasures or happiness.
  6. Purity, that is, how mixed it is with pain or displeasure.
  7. Extent, that is, how many people will be affected by the pleasure.

By taking these factors into consideration, we can evaluate the overall pleasure or happiness of an action or policy, with the one that produces the most pleasure or happiness being the one that is morally right.

The method is not without its fair share of criticism. For example, it does not take into account the different types of pleasure, such as the distinction between higher and lower pleasure as proposed by JS Mill, which we will be looking at in a moment.

Another difficulty faced by the hedonic calculus is difficulty of measurement. It is difficult to accurately measure and compare the intensity, duration, and other factors of happiness and pleasure.

It also doesn’t account for moral values such as justice, rights, and responsibility.

Furthermore, happiness and pleasure are subjective and may vary from person to person, therefore making their evaluation very difficult, if not impossible.


Rule utilitarianism, also known as “indirect utilitarianism”,  is an approach that focuses on the consequences of following general rules or principles.

JS Mill

Its origins can be traced back to JS Mill, emphasising individual liberty and the role of general rules and principles in promoting overall well-being. He introduced the idea of “higher” and “lower” pleasures, arguing that some pleasures are more valuable than others. Higher pleasures are more intellectual and refined and are associated with the cultivation of the mind and the development of one’s talents and abilities. Examples of higher pleasures include reading, having a conversation, or listening to music. They are considered to be more morally valuable because they are more enduring and satisfying in the long run.

Lower pleasures, on the other hand, are more physical and immediate, such as eating or having sex. These pleasures are considered to be less morally valuable because they are more fleeting and less satisfying in the long run.

Mill’s distinction is important because it allows for a more nuanced understanding of happiness and well-being.

Henry Sigwick

Henry Sigwick, in his 1874 book The Methods of Ethics, tried to address issues with act utilitarianism, such as its lack of attention to issues of justice and fairness. According to rule utilitarianism, a rule or principle is morally right if and only if, following that rule or principle would lead to the greatest overall well-being.

Under indirect utilitarianism, the moral value of a rule or principle is determined by its general consequences, rather than the specific consequences of each individual action.

iii. Utilitarianism and Consequences

Utilitarianism and consequentialism are closely related, but they are not the same thing. The former is a form of consequentialism, focusing on the overall well-being and happiness as the ultimate goal.

Consequentialism, on the other hand, is a broader ethical theory that states that the moral value of an action or policy should be determined by its consequences. It can be applied to different ethical theories, not just utilitarianism. For example, some forms of consequentialism may focus on the promotion of justice, or the protection of individual rights, rather than the promotion of overall well-being and happiness.

iv. Does the End Justify the Means?

An idea often associated with consequentialism is that the end justifies the means. The phrase is often used to suggest that the ultimate goal or outcome of an action or policy is more important that the methods used to achieve it. In other words, the morality of an action should be determined by its outcome, rather than the means by which it was achieved.

However, not all philosophers who have advocated for consequentialism have also advocated for the idea that “the end justifies the means.” Some have argued that it can be interpreted in a negative way, as it can be used to justify unethical actions, as long as they achieve a desired outcome. This can lead to moral dilemmas where the outcome is desirable, but the means to achieve it are not morally acceptable. An example where “the end justifies the means” can be tone deaf to moral nuance, empathy, and fairness, is Macchiavelli’s The Prince, from 1532. There, he argued that the ends of the ruler, such as the preservation of the state, justify the means used to achieve them, even if those means are morally questionable or reprehensible. Consequently, this would justify the use of force, deceit and cruelty.

For example, some argue that the end does not justify the means, if the means involve unfairness or injustice to certain individuals or groups. For example, if a policy is implemented to benefit the majority but harms a minority, it may be considered unjust, even if it achieves a desirable outcome.

Moreover, the idea that the end justifies the means can lead to a slippery slope where small immoral actions are justified in the name of a greater good, eventually leading to larger immoral actions.

It can also lead to lack of accountability and responsibility for the means used to achieve the end. The emphasis is on the end result, rather than the means used to achieve it. It can also create a mentality where individuals and organisations feel justified in using any means possible to achieve their goals, without considering the consequences of their actions.

Another objection is that it lacks moral integrity. The end would not justify the means if the means involve immoral or unethical actions. For example if a policy is implemented that involves lying, deception, or coercion in order to achieve a desirable outcome, it may be considered unethical. Some argue that certain actions are always morally wrong, regardless of their outcome. For example, it is wrong to kill an innocent person, even if doing so would lead to the prevention of greater harm.

v. Legacy

In response to criticism, utilitarianism has been refined and modified throughout the years by different philosophers, making it still relevant in 21st-century issues.

For example, utilitarianism’s focus on overall well-being, rather than individual pleasure, makes it relevant to contemporary ethical issues such as environmental ethics and sustainability. Sustainability requires considering the long-term well-being and happiness of society, as well as the well-being of future generations. Similarly, it is crucial to take into consideration the consequences of actions and policies in issues such as healthcare, poverty and climate change. In these issues, the consequences of different actions and policies can have a significant impact on the overall well-being and happiness of society.

The “trolley problem”, first proposed by philosopher Philippa Foot in 1967, has become increasingly relevant. It poses the following moral dilemma: there is a trolley moving towards a group of people who will die if it continues on its current course. However, you have the option to drive the trolley onto a different track, where it will hit only one person instead of many. The question is, is it morally right to divert the trolley onto the other track, even though it will result in the death of one person?

Utilitarianism would suggest that it is, indeed, morally right to do so, as it would result in the death of one person instead of many, promoting overall well-being and happiness for the majority of people.

In an increasingly automated society tending to artificial intelligence, machines need to make decisions based on mathematical calculations. Some of those decisions could very well be ethical. Some form of the hedonic calculus can be used to evaluate the moral value of different options and alternatives when making decisions in fields such as self-driving cars and military drone strikes.

In the case of self-driving cars, a hedonic calculus could be used to evaluate the potential consequences of different design choices, such as the level of autonomy, the speed of the vehicle, or the way in which the car handles certain situations. For example, a self-driving car that can make quick decisions and avoid accidents might be considered more morally valuable than one that prioritises passenger comfort over safety.

In the case of military drone strikes, a hedonic calculus can evaluate the potential consequences of different targeting decisions, such as the number of civilian casualties, the potential for collateral damage, or the effectiveness of the strike in achieving its objectives. For example, a drone strike that maximises civilian casualties and maximises the likelihood of success might be considered more morally valuable than one that prioritises speed and ease of execution.

In response, The Trolley problem has become increasingly relevant today as it raises important questions on whether we can deal so effectively with moral dilemmas by using mathematical formulas.

For example, a hedonic calculus would be based on the idea that pleasure can be quantified and compared, but it would not take into account the moral value of individual lives. It is mainly focused on maximising overall pleasure or happiness, but it’s difficult to say how many lives are worth sacrificing for the greater good.

Utilitarianism may be a simple idea, but its implications are far-reaching and thought-provoking. It forces us to confront difficult moral questions and weigh the impact of our actions on others. At its core, utilitarianism asks us to consider the greater good, to put aside our own interests, and to strive for a better world for all. This can be a powerful motivator for change, inspiring us to think beyond our own wants and needs, and to work towards a more just and equitable society. As we continue to face new ethical challenges in the 21st century, utilitarianism remains a valuable tool for navigating these complexities and for creating a better world for all. In the end, the true test of utilitarianism is not in its theories, but in our actions, and the impact they have on others.

Here are some books that can serve as good introductory texts on utilitarianism:

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