Sanctions and the Proof of Utility

Chapter 3 turns from what is right to what motivates people to do right. Mill uses the word "sanction" for the source of moral motivation: whatever pressure, internal or external, gets us to act in accordance with morality. He distinguishes two kinds.

External sanctions are pressures imposed from outside the person. The most obvious are legal: do this and you go to jail. But there are softer external sanctions too. Social pressure, whether the disapproval of your community, the loss of standing among your friends, or the threat of public shame, can be just as powerful as legal threats. Religious sanctions, where they are believed, add the prospect of divine punishment or reward. And there are reputational sanctions, the long-run consequences of being known as the kind of person who does or does not do certain things.

Mill thinks external sanctions matter but are not the whole story. A morality that only worked because of external pressure would collapse the moment external pressure was removed. People do what is right even when no one is watching, and Mill wants to explain why.

His answer is internal sanctions: the pressures we exert on ourselves. The most important is conscience, the sense of guilt or self-reproach we feel when we have done wrong, even if no one else knows. Mill thinks conscience is not a separate moral faculty given to us in advance (the way it might be for a religious thinker) but a learned, cultivated response. As we grow up in a moral community, we internalize that community's standards and come to feel guilt when we violate them. The feeling is real, but its source is social and developmental rather than metaphysical.

Behind the internal sanctions, Mill thinks, lies something even more basic: our natural sociability. Humans are constitutionally social creatures. We need others to survive in infancy, we depend on cooperative arrangements for almost everything in adulthood, and we have evolved deep psychological tendencies to identify with the people around us. Sympathy with others' joy and pain is not a moral achievement we have to argue for; it is a feature of human psychology that shows up reliably in normally developed people.

This social nature is what allows the principle of utility to motivate us in the first place. We are not just being told to count everyone's happiness equally as some abstract requirement. We are being told to take seriously something we already take seriously: the well-being of the people we live among. The principle of utility extends and systematizes a feeling we already have. It does not create the feeling out of nothing.

This explains why Mill thinks moral motivation does not require a special faculty or a divine commandment. We act morally because we are creatures who naturally care about other people, and the principle of utility is the systematic working-out of what that care commits us to. The external sanctions exist as backups for the cases where the natural feelings are insufficient or have been damaged, but the foundation is the social feeling itself.

It is worth noting how different this is from what we have seen in earlier units. Aristotle grounded morality in the function of a human being. Aquinas grounded it in the natural law God built into creation. Kant grounded it in the rational structure of the will. Mill grounds it in human sentiment: in the natural emotional responses of social creatures to one another. This is a much more naturalistic foundation, less ambitious metaphysically, and it leaves moral judgment more dependent on contingent facts about human psychology. Whether that is a strength or a weakness is one of the central debates about utilitarianism.

Chapter 4 takes up the question Mill has been avoiding throughout the book: what reason is there to accept the principle of utility itself? Why think happiness is the right standard for moral judgment, rather than some other candidate?

Mill begins with a concession. Ultimate principles cannot be proved in the strict sense, because proof always works by deriving a conclusion from something more basic, and an ultimate principle by definition has nothing more basic to derive it from. So whatever Mill is going to offer is not a strict logical proof. It is something looser: considerations that, if taken together, make it reasonable to accept the principle of utility as the foundation of morality.

What he offers is, essentially, the following argument. The only evidence we can have that something is visible is that people actually see it. The only evidence we can have that something is audible is that people actually hear it. By analogy, Mill says, the only evidence we can have that something is desirable is that people actually desire it. Now: everyone desires their own happiness. Therefore each person's happiness is good (to that person). Therefore the general happiness is good (in the aggregate, taking everyone into account). And this, Mill concludes, gives us the considerations we need to accept the principle of utility.

The argument has been criticized intensely since the day the book was published. The most famous criticism focuses on a single move: Mill's analogy between "visible" and "desirable."

There is a second move in Mill's proof that is worth flagging, because it surfaces a deeper philosophical problem we will return to in Chapter 5.

Mill argues: each person desires their own happiness, so each person's happiness is good to that person; therefore the general happiness is good in the aggregate to all of us collectively. This step looks innocent but actually does a lot of work. It moves from claims about what individual people want for themselves to claims about what is good from a collective, impersonal point of view.

Why is this controversial? Because each person desiring their own happiness does not obviously commit each person to caring about everyone's happiness. I can intensely value my own well-being and still feel no particular concern for the well-being of strangers. The fact that my happiness is a good to me, and your happiness is a good to you, does not by itself produce the conclusion that an impersonal sum of happiness across both of us is a good that anyone is obligated to promote. There is something missing in the inference.

Some philosophers think this gap can be bridged with additional argument; others think it cannot be bridged at all, and that consequentialist theories ultimately have to take "the good is to be impartially promoted" as an unargued first principle rather than something derivable from individual desires. Either way, this is a place where Mill's proof leans on an assumption that does much more work than it appears to do.

The aggregation problem becomes acute in Chapter 5, where Mill takes up justice. The cases where aggregation feels most morally problematic are cases where the sum of small benefits to many people seems to justify a large harm to one. Justice, on most accounts, is what protects individuals against being used as means to others' greater welfare. We will see in the next lecture how Mill tries to handle this.

It is worth pausing on what Chapter 4 has and has not accomplished.

What it has done: Mill has shown that we need some grounding for moral principles, that the kind of grounding available is not strict logical proof, and that the principle of utility has some considerations in its favor (people in fact value happiness, happiness is the kind of thing whose pursuit feels self-justifying, and so on).

What it has not done: Mill has not given a watertight argument that the principle of utility is true. His central proof has a serious flaw (the desired/desirable equivocation), and his move from individual to aggregate well-being papers over a real philosophical problem. The proof is suggestive rather than conclusive.

Most contemporary utilitarians acknowledge this and look for better grounds. Some argue that utilitarianism's appeal lies not in any logical derivation but in its impartiality (it treats everyone's interests equally) and its practical applicability (it gives clear guidance in cases where other theories give none). Others argue that the principle of utility captures something deep about what morality is for: making lives go better is the kind of thing morality should be about, even if we cannot prove this from outside morality.

For your purposes in this course, the important takeaways are these. Mill defends utilitarianism with one of the most famously flawed arguments in the history of philosophy. The flaw is real and worth understanding. But the flaw in a single argument does not refute the theory, and utilitarianism remains one of the major ethical traditions, with serious defenders to this day. When you evaluate utilitarianism in your reflection and your final paper, judge the theory itself, not just Mill's particular defense of it.