Unit 4: Overview

Suppose someone asks you whether an action was right or wrong. You could answer in two very different ways. You could look at the action itself: was it done for the right reasons, did it respect the people affected, did it follow a principle anyone could accept? Or you could look at what the action did: did it make people's lives better or worse, did it reduce suffering, did it produce more good than the alternatives?

Most people, when they think hard about morality, find themselves drawn to both kinds of answer. But the two approaches sometimes conflict. A truthful answer might wound someone unnecessarily. A broken promise might prevent a disaster. When intentions and consequences pull in opposite directions, which one settles the moral question?

John Stuart Mill's answer is that consequences settle it, and that the right measure of consequences is human happiness. His Utilitarianism, published in 1861, is the most influential defense of this position ever written. Mill argues that there is a single moral principle, the Greatest Happiness Principle, that grounds every genuine moral claim: actions are right insofar as they tend to promote happiness, wrong insofar as they tend to produce its opposite. Everything else, duties and rights and virtues and justice, is supposed to reduce to applications of this single principle, properly understood.

This is a bold reduction, and Mill knows it. Much of the book is devoted to defending utilitarianism against objections, including the most natural one: that consequences cannot be the whole story, because some actions seem wrong (lying, killing the innocent, breaking one's word) even when they would produce more happiness than the alternative. Mill's response is that these intuitions are not mistaken but are themselves utilitarian, properly understood. We have moral rules against lying because lies typically produce more harm than honesty does. The rules track utility; they do not stand apart from it.

Mill wrote in English, and his prose is much more accessible than Kant's. You will find his sentences long, in the Victorian style, but his arguments are usually clear once you slow down enough to follow the clause structure. Unlike Kant, Mill is writing for the educated public rather than for fellow philosophers; he wants you to be persuaded, and he writes accordingly.

That said, the book is structured oddly by modern standards. Chapter 1 is a brief preface. Chapter 2 is the heart of the book: it tells you what utilitarianism is and answers most of the standard objections. Chapter 3 takes up a psychological question (what motivates people to be moral?). Chapter 4 offers Mill's notorious "proof" of the principle of utility, which has been controversial since the day it was published. Chapter 5, the longest, is on justice. Each chapter does something different, and the connections between them are not always obvious. The lecture pages will help you see the through-line.

By the end of this unit, you should be able to:

• State the Greatest Happiness Principle and explain what makes it a consequentialist principle.
• Explain Mill's distinction between higher and lower pleasures and how it differs from Bentham's quantitative hedonism.
• Describe the main objections to utilitarianism that Mill addresses in Chapter 2, and assess how well his replies succeed.
• Distinguish external from internal sanctions and explain Mill's view of why people are motivated to act morally.
• Reconstruct Mill's "proof" of the principle of utility and identify the move at which the proof is most commonly challenged.
• Explain Mill's account of justice as a special class of utility, and assess whether his account succeeds in capturing what is distinctive about justice.
• Distinguish act utilitarianism from rule utilitarianism and apply each to a concrete case.

All of our Mill reading comes from a single text: Utilitarianism, the short book Mill published in 1861. The full text runs about sixty pages, is in the public domain, and is free to read online.

• Mill, Utilitarianism (1861), five chapters

The chapters are grouped into four parts, each paired with a lecture page in this unit.

• Chapter 1: General Remarks (paired with the Greatest Happiness lecture)
• Chapter 2: What Utilitarianism Is (paired with the Greatest Happiness lecture)
• Chapters 3–4: Sanctions of the Principle, and Mill's Proof (paired with the Proof and Sanctions lecture)
• Chapter 5: Justice and Utility (paired with the Justice lecture)

What you need to complete this unit

Work through each item in order.

• Read the lesson pages in this unit and watch the lecture videos on them
• Read the assigned text (see Readings above)
• Complete the reflection prompt
• Take the unit quiz