Lecture 1 · Part B — Ethical Theories as Lenses
An Introduction to Bioethics.
Plague reached Sicily in the autumn of 1347 and the Italian mainland that winter, then moved north city by city. Florence and Milan both knew it was coming, and both already believed it travelled with the sick, their belongings, and travellers from infected towns.
Florence did not act until the plague was already inside its walls, and could not enforce what it then ordered. It buried half its people, and possibly far more.
Milan sealed its gates early. When plague appeared in three houses, the ruling archbishop had them walled up with the occupants still inside, the healthy along with the sick and the dead. Milan came through comparatively lightly.
Sources and caveats. The walling-up is Barbara Tuchman’s account, which credits Archbishop Giovanni Visconti; she draws no causal conclusion from it, writing only that “whether or not owing to his promptitude, Milan escaped lightly in the roll of the dead” (Tuchman 1978). Milan’s escape was noticed at the time: the Florentine chronicler Matteo Villani recorded that the pestilence took the whole peninsula “with the exception of Milan and some Alpine districts of northern Lombardy” (Gasquet 1893). How much of that was policy, and how much Milan’s inland position and thinner sea trade, is unsettled. Florence was not idle, but it was late: its measures came in April 1348, after its first cases in March, and included a 500-lire fine on arrivals from Genoa and Pisa, a ban on selling the clothing of the sick, street clearing, and a magistracy with emergency powers (Henderson 1992). Estimates of Florentine mortality range from about half to four-fifths; the city’s population is usually put near 110,000 before the plague and about 50,000 by 1351. Benedictow is the standard survey of the mortality evidence (Benedictow 2021).
Each of those questions asks for a different kind of reason:
The three do not always agree. Which kind of reason a case turns on is often disputed, and here the dispute starts with whether Milan’s policy is the reason Milan survived.
In Part A we asked: what are the four principles, and how do you read a moral argument? Part B asks:
Where do the principles come from — and how do we weigh them when they conflict?
By the end of Part B, you will be able to:
The four principles tell you what to weigh. Theories tell you how.
The four principles — autonomy, beneficence, non-maleficence, justice — give us a shared vocabulary. But they do not, by themselves, tell us which principle to prioritize when they conflict (Beauchamp and Childress 2019).
Ethical theories fill that gap. Think of them as lenses:
We will use these lenses throughout the course — not to pick a winner, but to see more of the problem.
| Lens | Core question | Key figures |
|---|---|---|
| Utilitarianism | What produces the best outcomes for all affected? | Bentham, Mill; Singer |
| Kantian ethics | What do we owe persons, regardless of outcome? | Kant; O’Neill, Kamm |
| Character & traditions | What kind of person, relationship, and community is good? | Aristotle; Gilligan/Held, Confucius, Aquinas |
The four principles are the shared backdrop all three lenses interpret — differently.
These four theories reappear in almost every chapter that follows. Abortion, end of life, justice — each one sets them pulling in different directions. Noticing which theory is doing the work in an argument is half of reading it well.
The right action produces the greatest good for the greatest number.
“The creed which accepts as the foundation of morals, Utility, or the Greatest Happiness Principle, holds that actions are right in proportion as they tend to promote happiness, wrong as they tend to produce the reverse of happiness. By happiness is intended pleasure, and the absence of pain; by unhappiness, pain, and the privation of pleasure.”
J. S. Mill, Utilitarianism (1863) (Mill 1863)

Utilitarianism judges actions entirely by their consequences:
Bentham called this the hedonic calculus — weigh the pleasures and pains produced, add them up, choose the highest score (Bentham 1789).

Beneficence is central — acting to maximize welfare just is acting beneficently.
Justice emerges from impartiality: each person counts as one, so unfair distributions that reduce total welfare are wrong.
Autonomy is valued instrumentally — respecting autonomy usually maximizes welfare — but can be overridden when it doesn’t.
Non-Maleficence is captured under the harm side of the ledger.
Note
The tension. A strict utilitarian could justify deceiving a patient if the deception produces better outcomes. Most clinicians resist this — which is why other theories matter.
A city has 10 ventilators and 15 patients who need one to survive. Five of the fifteen have a much higher probability of surviving with ventilator support.
A utilitarian protocol would allocate ventilators to maximize lives saved — which likely means the five highest-probability patients get priority.
Note
The utilitarian reply. A sophisticated utilitarian can say: the protocol maximizes welfare across the group, which is what justice requires.
The critique is that it treats some lives as worth less, and that the reasons behind lower survival odds (disability, chronic illness) are often tied to existing inequities. We will return to this when we take up public health ethics and the just allocation of care.
The drowning child. You pass a shallow pond where a small child is drowning. Wading in ruins your expensive shoes — obviously you must save her. Singer asks: why is a child dying of a preventable disease overseas any different? (Singer 1972)
Singer matters precisely because he refuses to stop where intuition gets uncomfortable. This is the hinge of the chapter: the next section asks whether “follow the calculation wherever it leads” is the right method at all.
Act from duty — treat persons always as ends, never merely as means.

Immanuel Kant (1724–1804) argued that morality is grounded in reason, not consequences.
The key test is his Categorical Imperative — a rule for whether an action is morally permissible, applied before you look at outcomes.
The most clinically relevant form of the Categorical Imperative (Kant 1785):
“Now I say: man and generally any rational being exists as an end in himself, not merely as a means to be arbitrarily used by this or that will.… So act as to treat humanity, whether in thine own person or in that of any other, in every case as an end withal, never as means only.”
Kant, Groundwork of the Metaphysic of Morals (1785), trans. T. K. Abbott (Kant 1785)
Autonomy is Kant’s central principle — respecting autonomy is what it means to treat persons as ends.
Non-Maleficence reflects the duty not to harm persons who have inherent dignity.
Beneficence is a genuine duty, but cannot override autonomy — benefiting someone by deceiving them is still wrong.
Justice flows from treating persons equally as ends — no one’s dignity is worth more than another’s.
Note
Contrast with utilitarianism. Kant would say: you must never lie to the Jehovah’s Witness patient about her prognosis to get her to consent, even if lying would save her life.
A patient with severe depression has been refusing an antidepressant. His psychiatrist suspects the refusal is itself a symptom of the illness — that his depression is preventing him from appreciating how treatment could help him.
Note
The Kantian tension. Kant’s framework requires that the patient be capable of rational self-governance for autonomy to apply fully. If the illness itself impairs that capacity, overriding expressed wishes may be consistent with treating him as an end — but this reasoning can also be abused to justify paternalism.
Decision-making capacity assessment is how clinical ethics tries to hold this line carefully.
| Issue | Singer (preference utilitarian) | Kantian ethics (constraints, dignity) |
|---|---|---|
| Global poverty | Strong duty to give; distance irrelevant; very demanding | A real but bounded duty to aid; owed first to particular others |
| Animals | Equal consideration of like interests; speciesism is a bias | Treatment is still constrained, but duties often track rational agency |
| End of life | Personhood and preferences decide; voluntary euthanasia permissible | Persons have dignity; you may not use or kill a person for net benefit |
| Method | Sum the interests, choose the maximum | Apply constraints first; numbers do not settle everything |
Same cases, different moral currency — which is why we keep both lenses on the table.
The third lens: not “what rule?” or “what calculation?” but “what kind of person, relationship, and community is good?”
These traditions judge the agent and the relationship, not only the isolated act — but they differ sharply:

Aristotle asked not “what should I do?” but “what kind of person should I be?” (Aristotle 340 BC)
Eudaimonia — often translated flourishing — is the goal of human life: living and acting in accordance with the virtues of a fully developed human being.
A virtue is a stable character trait — developed through practice — that reliably disposes a person to act and feel well.
Virtue ethics is especially useful in professional ethics, because professions define role-specific excellences.
The ANA Code of Ethics (American Nurses Association 2015) describes the good nurse as someone who embodies:
These are not policies. They are traits you develop by practicing them.
Virtue ethics asks: what would a person of good character do in this situation?
Beneficence — the virtuous clinician genuinely cares about the patient’s good, not just follows protocols.
Non-Maleficence — integrity means honesty about what you can and cannot do.
Autonomy — respect for persons flows from compassion and fidelity, not just rules.
Justice — fairness requires the virtue of impartiality even toward patients you find difficult.
“[T]he moral problem arises from conflicting responsibilities rather than from competing rights.”
— Gilligan, In a Different Voice (1982)


A 78-year-old woman with mild cognitive impairment makes decisions that worry her adult children. She insists on living alone; she sometimes forgets meals; she declines the assisted living facility they have arranged.
Note
What the relational lenses add. They center the relationship and her embeddedness in family and community — her story, not just her risk score; the Confucian frame even treats the family as a proper decision-maker.
What they can obscure: a caring family can also be a controlling one, so these lenses still need justice to ask whether the relationships are themselves fair. This is why the four principles are used alongside the theories, not replaced by any single one.
Four lenses. One case. Different things come into view.
Return to the choice between Florence’s policy and Milan’s. Which kind of reason carried the most weight for you, and does it still?
| Lens | Foundational commitment | Role of the four principles |
|---|---|---|
| Utilitarianism | Maximize welfare for all affected | Principles are derived — follow them because doing so usually produces the best outcomes |
| Kantian ethics | Respect persons as ends | Principles are duties grounded in rational dignity — especially autonomy |
| Character & traditions | Cultivate good character and right relationship | Principles are expressions of virtue and relationship — wisdom and context tell you how to apply them |
Probably none of them — completely. Each illuminates something the others miss:
The four principles work in part because they are theory-agnostic: a Kantian and a utilitarian can both endorse autonomy, beneficence, non-maleficence, and justice — they just disagree about why and how to weight them.
Bioethics uses a four-principle framework as its shared vocabulary, supported by major ethical theories that answer how to weigh those principles differently. Utilitarianism focuses on outcomes and aggregate welfare — Singer pushes that logic to its hardest conclusions. Kantian ethics focuses on duties and the dignity of persons — O’Neill and Kamm answer Singer by rebuilding moral constraints. The character traditions — virtue, care, Confucian, and natural law — focus on the kind of person, relationship, and community we should sustain. No single theory is correct; used as lenses, they let us see more of what is morally at stake in any clinical situation.
Next, we turn to the history that gave these principles their urgency, and the clinical relationship where they are daily tested.
Recall
What makes an action right for a utilitarian, for a Kantian, and for a virtue or care ethicist?
Apply
A clinician considers giving a placebo pill without disclosing it to a patient with chronic pain because it may relieve symptoms and seems harmless. How would a utilitarian, a Kantian, and a care or virtue ethicist evaluate that choice?
Debate
Should global-health funding be directed mainly by cost-effectiveness calculations that maximize total benefit, or should relationship-based duties, local priorities, and historical injustice sometimes override that math?
Bioethics OER · CC BY-NC 4.0 · Brendan Shea