An Introduction to John Stuart Mill

Austin Tannenbaum
11 min readSep 12, 2021


John Stuart Mill was an English philosopher who devoted his life to the cause of utilitarianism: the ethical vision that society should be governed in a manner that maximizes happiness for the greatest number. Mill was born May 20, 1806 in a London suburb. His father James was an important philosopher in his own right, collaborating with utilitarianism’s founder Jeremy Bentham and co-leading the Radicals movement in English politics, which promoted reason, industrialization, and democracy. James sought to turn John into a “genius intellect” capable of carrying the torch of utilitarianism, subjecting Mill to a rigorous study regiment from a very early age. By three, Mill had learned Greek. By six, he had successfully read through many of the Classics. By eight, he had mastered mathematics and Latin, perusing popular science texts and literature in his spare time.

As the eldest child, Mill was tasked with educating his eight younger siblings. He was also required to take daily walks with his father and report on what he had learned that day. Mill had a rich intellectual upbringing, spending time with famous thinkers of the day including economists David Ricardo and Jean Baptiste Say along with Bentham and his brother. Although he never attended a formal university, Mill founded intellectual societies, participated in debates, headed study groups, and wrote for periodicals such as The Westminster Review.

But there was trouble in paradise. The stress of Mill’s rigorous academic training caused him to suffer a nervous breakdown. The young Mill, whose life had been dedicated to promoting his father’s vision of the world, asked himself whether he would be happy upon achieving it. To his horror, he answered no. Devoid of meaning, he fell into a deep depression, even contemplating suicide.

What saved him was not some logical proof for why life is preferable to death, but the life-affirming poetry of Wordsworth. Mill realized that while his analytical faculties had been expertly honed, his capacity for feeling had been neglected — a capacity he began to cultivate through the arts. Recognizing beauty as indispensable to happiness in its power to stimulate joy and generate compassion, Mill featured aesthetics prominently in his later philosophy.

As a young man, Mill angered religious authorities by preaching tolerance and rejecting the Church of England’s Thirty Nine Articles — strict religious doctrines to which all church members were required to adhere, for example that penance is necessary for salvation and that the Eucharist is literally the body and blood of Christ. Brought up secular, Mill held that theodicy precluded the possibility of a simultaneously benevolent and omnipotent God. Due to these and other heresies, Mill was banned from studying at British universities and instead went right to work at the East India Company under his father. The East India Company was a private colonial venture that Mill supported on the grounds that a “benevolent despotism” was necessary to civilize “barbarous” regions. He worked there until 1858, when the Company was dissolved in favor of direct government control of India, which Mill opposed. After declining a post in the new administration, Mill retired on a pension of 1,500 pounds.

In 1851, Mill married philosopher and women’s rights advocate Harriet Taylor, whom he described as his intellectual equal and a major influence on his social philosophy. They had been friends for two decades prior, while Harriet was married to another man. She died from pneumonia just seven years after the two eloped.

In his mature years, Mill continued to speak and write, and served as rector of the University of St. Andrews. In 1865, he was elected to the British parliament, where he advocated for women’s suffrage, labor unions, farm cooperatives, and proportional representation. After contracting a bacterial infection, Mill passed away three days before his 67th birthday. His last words were, “You know that I have done my work.”

The political theory for which Mill is famous is grounded in a “radical empiricism” that roots all knowledge in sensory experience. Mill discounts the possibility of purely a priori knowledge (knowledge arrived at prior to experience), holding that even the most seemingly theoretical knowledge, including that of mathematics and logic, is made possible by observation. For instance, we cannot know that 1 + 1 = 2 until we see one object joined with another. Similarly, we cannot know the law of identity (A = A) until we perceive two identical substances in nature.

Specifically, Mill holds that no new knowledge can be derived from a priori reasoning; the most it is capable of is making clear what is already implicitly known. To give an example, the proposition “All bachelors are unmarried” has its conclusion definitionally contained in its premise: a bachelor is an unmarried man. This sort of self-evident proposition is helpful in verifying what we think we know, but it cannot help us discover what we do not. For that, an inductive approach is required, wherein we observe the world and then reflect on what we’ve perceived. Following his empiricist predecessor John Locke, Mill promotes an “associationist” model of knowledge production in which the simple ideas received through the senses are combined in various ways by the intellect to produce complex ideas.

Mill’s epistemology has at least a few important practical consequences. Firstly, it condemns the sort of speculative reasoning that often leads to dogma. Knowledge ought to be adopted after thorough testing rather than decreed from on high. Subjecting all beliefs to scrutiny moves society forward, whereas clinging to inviolable superstitions blocks progress. Secondly, because all ideas are derived from experience, we must take care to create an environment that instills ideas of social cohesion, especially in early childhood, when one’s worldview is still being shaped. Finally, since we form complex ideas through association, it is crucial that we corroborate associations (e.g. that y effect really is the result of x cause) before adopting them as beliefs. Indeed, Mill regards false beliefs as the product of incorrectly associating two ideas together, either through sloppy reasoning or bias.

Mill approaches utilitarianism in this observational manner, investigating whether morality really is a function of what maximizes happiness. In describing the principle of utility, Mill writes,

“Actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness.”

By happiness, Mill simply means pleasure and lack of pain. In contrast, unhappiness is lack of pleasure and presence of pain. Note that the type of pleasure and pain Mill is envisioning is psychological rather than physical. Consider, for instance, that one may be physically pained during a rigorous workout, but psychologically pleased at the fitness boost it will confer.

In defending the principle of utility against common criticisms, Mill makes two important qualifications. First, he distinguishes the carnal pleasure of the body from the intellectual and moral pleasures of the mind, which are said to be more conducive to happiness and thus of a higher quality. Countering the claim that utilitarianism promotes hedonism, Mill remarks that “it is better to be a human being dissatisfied than a pig satisfied.” Secondly, Mill clarifies that utilitarianism’s aim is to maximize social rather than individual happiness, writing that “the standard is not the agent’s own greatest happiness, but the greatest amount of happiness altogether.”

While these responses put to rest the idea that utilitarianism is a selfish philosophy, an important question remains: why choose happiness as our moral standard? Mill answers in the tradition of Aristotle, arguing that happiness is the only thing we desire for itself, with everything else being a means to its end. Mill challenges his readers to identify a desire whose ultimate aim is anything other than happiness.

Finally, Mill defends the viability of his project by appealing to human nature. Mill claims that humans have moral instincts such as compassion, guilt, and empathy that cause us to be pleased by the pleasure of others and pained by the pain of others. As a result, we desire not only our own happiness, but also the happiness of others, which makes the project of creating a society that adopts the principle of utility at least possible, and therefore worth striving for.

While the principle of utility is fixed, its application in real-life situations requires observation and deliberation among members of a society. To this end, Mill defends the importance of liberty, which he describes as freedom from tyranny. Uncontroversially, Mill recognizes political tyranny as a despot’s violent repression of what citizens can say and do. However, he also identifies a less obvious form of social tyranny — a “tyranny of…prevailing opinion” — more insidious than outright authoritarianism:

“Though not usually upheld by such extreme penalties, social tyranny leaves fewer means of escape, penetrating much more deeply into the details of life, and enslaving the soul itself.”

Mill notes that while political tyranny emboldens true believers to champion their ideals, social tyranny “induces men to disguise them, or to abstain from any active effort for their diffusion.” Given this, it is all the more important to vigilantly protect free speech in all cases — if the speech is true, mixed, or even false.

Clearly, free speech ought to be protected when the speech is true, as airing true opinions advances our knowledge while censoring them hinders it. The condemnation of heliocentrism by the Church, for example, held back the field of astronomy for centuries.

In cases where speech is partially true and partially false, permitting its expression honors the complexity of the world and strengthens truth by adding context and nuance. In the dialectical tradition of Hegel, Mill remarks that,

“Truth, in the great practical concerns of life, is so much a question of the reconciling and combining of opposites.”

By introducing ideas to each other, the one-sidedness of each idea is exposed, and, with effort, the two are synthesized in a richer and more intellectually satisfying whole. Jean-Jacques Rousseau’s arguments about the benevolence of nature and the malevolence of society, for instance, were flawed, but offered valuable insights into the pitfalls of the modern world that helped temper the excesses of Enlightenment optimism.

Most controversially, Mill contests that the free expression of false speech ought to be protected. One reason why is that false opinions are more effectively rooted out by confronting them head on. Exposing the falseness of an idea demonstrates why it shouldn’t be adopted, whereas censoring an idea gives its proponents the opportunity to claim the moral high ground, alleging that the powers that be are silencing them out of fear of the truth. Another reason is that by refuting false ideas, we are afforded a better understanding of the truth. If certain truths become so sacrosanct that they are no longer open to debate, our “living truths” become “dead dogmas” and our relationship to truth becomes one of rote memorization and regurgitation rather than genuine understanding. Finally, uninformed bystanders risk being beguiled into believing false ideas in the absence of a counterargument.

Ultimately, Mill holds that knowledge is reliable in proportion to the degree to which it withstands challenges and refines itself accordingly. He notes that even the Church has a “devil’s advocate” who provides arguments against canonizing individuals under consideration for sainthood. Even if the probability of an idea being incorrect is slim, society is made better by allowing it to be publicly scrutinized. This is why social tyranny is so chilling: by censoring speech, we silence dissenting opinions, which are the motor of positive revision of our collective knowledge. In Mill’s words,

“Unmeasured vituperation, employed on the side of prevailing opinion, really does deter people from expressing contrary opinions, and from listening to those who express them.”

Mill does carve out one exception to the principle of free speech, known as the harm principle:

“The only purpose for which power can be rightfully exercised over any member of a civilized community, against his will, is to prevent harm to others.”

For speech to constitute a violation of the harm principle, it must not merely offend — an inevitability when closely held ideas are challenged — but cause direct physical injury to another. In all other cases, we ought not to interfere with an individual’s free speech. Mill writes that while we may,

“…remonstrate with him, or reason with him, or persuade him, or entreat him, [we may] not…compel him, or visit him with any evil, in case he do otherwise. The only part of the conduct of any one, for which he is amenable to society, is that which concerns others. In the part which merely concerns himself, his independence is, of right, absolute. Over himself, over his own body and mind, the individual is sovereign.”

In Marxian fashion, Mill recognizes that our ideas about the world often come from those in power who are able to dictate society’s moral agenda:

“Wherever there is an ascendant class, a large portion of the morality of the country emanates from its class interests, and its feelings of class superiority.”

In this light, it is unsurprising that the early Mill inherited his economic stances from the bourgeoisie of his time, advocating for free markets and flat taxes. However, after reading radical utopian thinkers such as Robert Owen and Charles Fourier, Mill became a self-identified socialist, promoting free education, cooperative ownership of businesses, and a more equitable distribution of the means of production to facilitate “equality of opportunity.” It should be noted that Mill sought to maintain competition, envisioning a benevolent meritocracy rather than a society guaranteeing an exact equality of outcome. Mill was explicit in his condemnation of capitalism’s industrialization and specialization, which he felt led to a spiritual and moral deadening. His core belief was that every human deserves to have their basic needs met and that society was doing a far poorer job than it was capable of in providing for those needs.

Mill recognized that this was particularly true for marginalized groups. He argued for the abolition of slavery, calling it an “unmitigated abhorrence to all but the very few who profited from it.” He went a step further than most by pushing for reparations to former slaves in the form of “land given to every negro family.”

With regard to women, Mill was one of the earliest male proponents of feminism. In The Subjection of Women, Mill highlighted many of the ways that women in his time were treated as inferior:

  • Women had fewer grounds for divorce than men.
  • Women were forced to forfeit their personal property to their husbands.
  • Women lacked custody over their children, with their husbands possessing sole custody.
  • Women could not have their allegations of rape against their husbands legally considered.
  • Women lacked the right to vote.

Mill saw that treating women as second class citizens produced a host of negative effects, stunting women’s intellectual development, forcing them into self-sacrifice, shrinking their worlds, and subjecting them to brutal treatment by men. The stereotype of female pettiness and irritability was, to Mill, in reality women’s emotional distress at their lack of rights and social dignity. Mill maintained that the only acceptable solution to sexism was “a principle of perfect equality” in the legal treatment of women vis-à-vis men.

Mill was a believer in free will, asserting that despite our inability to choose what we desire, we nonetheless maintain the ability to choose how we act. He was very interested in how our social environment influences our moral decision-making, even proposing a field called “ethology” to investigate how different environments affect the creation of human character and identify the optimal conditions for socially engineering moral citizens. Viewing history as “the unfolding of a great epic or dramatic action terminating in the happiness or misery of the human race,” Mill emphasized individual action, drawing attention to the fact that in our “unremitting conflict between good and evil powers, every act done by any of us, insignificant as we are, forms one of the incidents.” Mill advocated free universal education, available to all genders and races, to teach the “indissoluble association between [an individual’s] own happiness and the good of the whole” in hopes of achieving his vision for a free, utilitarian society.