Sources and References

• Bertrand Russell, The Problems of Philosophy (1912), Chapter XV: “The Value of Philosophy”
• Aristotle, Physics, Book II, Section 3; Nicomachean Ethics, Book III
• Teresa of Avila, The Interior Castle (1577), Preface and First Mansions (pp. 15–25)
• Rene Descartes, Meditations on First Philosophy (1641)
• Princess Elisabeth of Bohemia and Rene Descartes, Correspondence of June–July 1643, in The Correspondence between Princess Elisabeth of Bohemia and Rene Descartes, ed. Lisa Shapiro (University of Chicago Press, 2007)
• Jorge Luis Borges, “The Library of Babel” (1941), in Ficciones
• John Locke, An Essay Concerning Human Understanding (1689), Book II, Ch. 1 and Ch. 8
• George Berkeley, A Treatise Concerning the Principles of Human Knowledge (1710), Sections 1–33
• Karl Popper, The Logic of Scientific Discovery (1959); Conjectures and Refutations (1963)
• Thomas Kuhn, The Structure of Scientific Revolutions (1962), Introduction
• Helen Longino, Science as Social Knowledge (1990)
• W. V. O. Quine, “Two Dogmas of Empiricism” (1951)
• Sophocles, Oedipus Rex (c. 429 BCE)
• Ted Chiang, “Story of Your Life” (1998), in Stories of Your Life and Others
• Stanford Encyclopedia of Philosophy entries on Descartes, Elisabeth of Bohemia, Berkeley, Popper, Kuhn, Free Will, and Aristotle on Causality

Chapter 1: What Is Philosophy?

1.1 The Russell Question: Why Does Philosophy Matter?

Bertrand Russell opens The Problems of Philosophy (1912) by confronting a blunt question: if philosophy cannot give us definitive answers the way science can, why bother with it at all? His answer in the final chapter, “The Value of Philosophy,” has become one of the most widely read introductions to philosophical thinking ever written.

Russell argues that philosophy’s value lies not in providing final answers but in the questions themselves. The person who never philosophizes “goes through life imprisoned in the prejudices derived from common sense, from the habitual beliefs of his age or his nation.” Such a person finds the world “definite, finite, obvious.” Philosophy breaks open this complacency. By raising doubts about what we normally take for granted, philosophy “enlarges our thoughts and frees them from the tyranny of custom.”

The Practical Person’s Objection

Russell anticipates the objection of the “practical” person who dismisses philosophy as useless because it produces no tangible goods. He replies that this objection confuses the value of philosophy with the value of the physical sciences. The sciences began as parts of philosophy and separated once they could provide definite answers. What remains within philosophy are precisely those questions for which definite answers have not yet been found — but these are also the most profound questions human beings can ask.

Philosophy as Liberation

The chief value of philosophy, for Russell, is contemplation — the capacity to consider questions without the distortion of personal bias or narrow self-interest. The “free intellect” sees things as they are, “without the desire to prove them good or bad.” Through this expansion of the self, philosophy makes us citizens of the universe rather than prisoners of our own limited perspective.

Why This Course Exists

Dr. Fehr’s course description echoes Russell’s vision. The course is about “creating a good life while engaging challenging ideas.” Students will explore ideas that challenge what they really know, what they should believe, and how much control they have over their choices. The hope is that, by the end, students will respond to challenging ideas “with curiosity, integrity, and joy.”

Chapter 2: The Art of Reasoning: Logic and Fallacies

2.1 Why Logic Matters

Before diving into philosophical content, this course equips students with the tools of reasoning. Logic (逻辑学) is the study of the principles of valid inference and correct reasoning. In philosophy, arguments are the currency of exchange: you do not simply state your opinion; you give reasons for it, and those reasons must hang together in the right way.

2.2 The Structure of Arguments

An argument (论证) in philosophy is not a quarrel. It is a set of statements — called premises (前提) — offered in support of another statement — the conclusion (结论).

Validity and Soundness

Two key concepts govern the evaluation of arguments:

• Validity (有效性): An argument is valid if, assuming the premises are true, the conclusion must be true. Validity is about the structure of the argument, not whether the premises are actually true.
• Soundness (可靠性): An argument is sound if it is valid and all its premises are actually true. A sound argument guarantees a true conclusion.

2.3 Common Logical Forms

Modus Ponens

If P, then Q. P. Therefore, Q.

This is one of the most basic valid argument forms. For instance: “If it rains, the ground is wet. It is raining. Therefore, the ground is wet.”

Modus Tollens

If P, then Q. Not Q. Therefore, not P.

For instance: “If the cake is done, the toothpick comes out clean. The toothpick does not come out clean. Therefore, the cake is not done.”

Disjunctive Syllogism

Either P or Q. Not P. Therefore, Q.

2.4 Informal Fallacies

A fallacy (谬误) is a defect in an argument that makes it appear stronger than it really is. Informal fallacies are errors in reasoning that arise from the content or context of the argument rather than from its logical structure.

Common Fallacies

Ad Hominem (人身攻击谬误): Attacking the person making the argument rather than the argument itself. “You say exercise is healthy, but you never exercise, so your argument is wrong.” The speaker’s habits are irrelevant to whether the claim is true.

Straw Man (稻草人谬误): Misrepresenting someone’s argument to make it easier to attack. Instead of addressing the actual position, the critic attacks a weaker, distorted version.

Appeal to Authority (诉诸权威): Citing an authority figure who is not an expert in the relevant field. A celebrity endorsing a medical treatment is not evidence for its effectiveness.

Appeal to Ignorance (诉诸无知): Arguing that something is true because it has not been proven false, or vice versa. “No one has proven that ghosts do not exist, so they must exist.”

Equivocation (歧义谬误): Using a word with two different meanings in the same argument, creating the illusion of a valid inference.

Begging the Question (循环论证/窃取论题): Assuming the conclusion in one of the premises. “God exists because the Bible says so, and the Bible is true because it is the word of God.”

False Dilemma (虚假二难): Presenting only two options when more exist. “You are either with us or against us.”

Slippery Slope (滑坡谬误): Arguing that one event will inevitably lead to a chain of negative consequences without adequate justification for each link.

Chapter 3: Aristotle’s Four Causes and Common Sense

3.1 Aristotle and the Question of Explanation

Aristotle (384–322 BCE) is one of the most influential philosophers in Western history. A student of Plato, he wrote on virtually every subject: logic, biology, physics, ethics, politics, and metaphysics. In Physics Book II, Section 3, Aristotle asks a deceptively simple question: what does it mean to explain something?

3.2 The Four Causes

Aristotle argues that a complete explanation of any natural thing or artifact requires four types of cause:

1. Material Cause (质料因)

The material cause is what something is made of. A bronze statue’s material cause is bronze. A wooden table’s material cause is wood. The material constrains and enables what the thing can become.

2. Formal Cause (形式因)

The formal cause is what something is — its form, structure, pattern, or essence. The formal cause of a statue is its shape; the formal cause of a human being is the arrangement and organization that makes it a human rather than something else. Aristotle closely links the formal cause to the definition of a thing.

3. Efficient Cause (动力因)

The efficient cause is the agent or process that brings something into being. This is closest to what modern people typically mean by “cause.” The sculptor is the efficient cause of the statue; the parents are the efficient cause of a child.

4. Final Cause (目的因)

The final cause is the purpose or end for which something exists or is done. The final cause of a knife is cutting; the final cause of an acorn is to become an oak tree. Aristotle calls this the “that for the sake of which.”

3.3 Why Four Causes? Common Sense and Its Limits

Aristotle’s four causes represent what he considers a common-sense framework for understanding the world. We naturally appeal to all four types of explanation in everyday life, even if modern science tends to focus primarily on efficient causation.

The Controversial Final Cause

The most philosophically contentious cause is the final cause. Modern science, especially since the seventeenth century, has been suspicious of final causes (also called teleology, 目的论). Why? Because attributing purposes to nature seems to imply that natural objects have intentions or goals. A physicist explaining why a ball falls does not say the ball “wants” to reach the ground.

Aristotle, however, insists that final causes are indispensable for understanding natural processes. An acorn does not randomly turn into an oak tree — it develops toward a specific end. For Aristotle, nature is permeated with purposive processes, even when no conscious intention is involved.

3.4 Aristotle’s Legacy in This Course

Aristotle reappears later in this course in the context of free will and voluntary action (Chapter 6). His four-causes framework also provides a useful contrast with the modern philosophy of science explored in Chapter 5. The tension between Aristotelian common sense and the reductive explanations of modern science is one of the enduring themes of philosophy.

Chapter 4: Epistemology — Knowledge, Doubt, and Reality

4.1 What Is Epistemology?

Epistemology (认识论) is the branch of philosophy concerned with knowledge: What can we know? How do we know it? What are the limits of human understanding? This chapter traces an extraordinary arc of thinking about these questions, from the introspective mysticism of Teresa of Avila through the radical doubt of Descartes, the sharp critical intervention of Princess Elisabeth, and the empiricist theories of Locke and Berkeley.

4.2 Teresa of Avila: Self-Knowledge and the Interior Castle

The Thinker

Teresa of Avila (1515–1582) was a Spanish Carmelite nun, mystic, writer, and reformer. She was one of the first women to be declared a Doctor of the Church. Her masterpiece, The Interior Castle (1577), uses the extended metaphor of a castle with many mansions to describe the soul’s journey toward self-knowledge and union with God.

The Castle Metaphor

Teresa envisions the soul as a crystal castle containing seven sets of mansions (moradas). God dwells at the very center. The journey inward through the mansions represents stages of increasing self-awareness and spiritual depth.

The First Mansions: Entering the Castle

In the Preface and the First Mansions (pp. 15–25), Teresa lays out the starting point of the journey. Most people, she says, never enter the castle at all — they remain outside, distracted by worldly concerns, unaware of the richness of their own inner life. Those who begin to enter the castle must start with humility (谦逊): the “room of self-knowledge” is the foundation for all further progress.

Teresa warns against two dangers:

1. Self-absorption without humility — dwelling on one’s faults in a way that breeds fear and paralysis rather than growth.
2. Spiritual pride — rushing ahead to the “higher mansions” without first cultivating genuine self-knowledge.

Philosophical Significance

Teresa’s contribution to epistemology is her insistence that knowing yourself is the prerequisite for knowing anything else. This is not a trivial claim. It anticipates later philosophical concerns about the relationship between the knower and the known. If you do not understand the nature and limitations of your own mind, how can you trust what it tells you about the world?

Teresa also raises the question of epistemic humility — the idea that genuine knowledge requires acknowledging how much you do not know. This theme resonates throughout the course, from Descartes’s method of doubt to Russell’s argument that philosophy enlarges the mind precisely by showing us the limits of certainty.

4.3 Descartes: The Method of Doubt

The Thinker

Rene Descartes (1596–1650) is often called the “father of modern philosophy.” A French philosopher, mathematician, and scientist, he sought to rebuild human knowledge on absolutely certain foundations. His Meditations on First Philosophy (1641) is one of the most important texts in Western philosophy.

The Project of the Meditations

Descartes begins with a radical premise: everything he has ever believed might be wrong. He resolves to doubt everything that can possibly be doubted, in order to find — if possible — something that cannot be doubted at all. This is the method of doubt (怀疑方法), also called methodological skepticism (方法论怀疑主义).

Stages of Doubt

Descartes proceeds through increasingly extreme levels of doubt:

Stage 1 — The senses deceive. Our senses sometimes mislead us (a stick in water looks bent; distant towers look round but are square). If the senses have deceived us before, can we ever fully trust them?

Stage 2 — The dream argument. How do you know you are not dreaming right now? In dreams, everything seems real. There is no reliable internal mark that distinguishes waking experience from dreaming.

Stage 3 — The evil demon. Descartes introduces the hypothesis of a supremely powerful and malicious deceiver — an evil demon (malin genie, 邪恶精灵假设) — who devotes all its energy to tricking us. Under this hypothesis, even mathematical truths like 2 + 3 = 5 might be illusions planted in our minds.

The Cogito

Having doubted everything, Descartes discovers one thing that survives all doubt:

The Cogito is not a logical argument in the traditional sense (premise, premise, conclusion). It is more like a self-verifying insight: whenever I think about whether I exist, the answer is necessarily “yes,” because the thinking itself proves my existence.

What Am I?

From the Cogito, Descartes concludes that he is essentially a thinking thing (res cogitans, 思维实体) — a mind. He can conceive of himself existing without a body, but he cannot conceive of himself existing without thought. This leads to substance dualism (实体二元论): the view that mind and body are two fundamentally different kinds of substance.

• Mind (res cogitans): unextended (takes up no space), conscious, thinking.
• Body (res extensa, 广延实体): extended in space, subject to physical laws, not conscious.

4.4 Princess Elisabeth and the Mind-Body Problem

The Thinker

Princess Elisabeth of Bohemia (1618–1680) was the eldest daughter of Frederick V, Elector Palatine, and Elizabeth Stuart. Educated in multiple languages, mathematics, and philosophy, she initiated a philosophical correspondence with Descartes in 1643 that continued until his death in 1650. Elisabeth is increasingly recognized as a major philosopher in her own right — not merely a “student” of Descartes but a critical interlocutor who identified what many consider the fatal weakness in his system.

The Correspondence of June–July 1643

The exchange of letters in this course covers three pivotal texts:

Elisabeth to Descartes, 16 May 1643 (leading to the June 10 letter)

Elisabeth writes to Descartes with a question that is disarmingly simple yet devastatingly effective: How can the soul, which is unextended (takes up no space), cause the body, which is extended (occupies space), to move?

Elisabeth points out that all the causal interactions we understand involve physical contact: one billiard ball strikes another; a hand pushes a door. These interactions require that both things involved have extension — they must occupy space so they can make contact. But Descartes has defined the mind as unextended. So how can it make contact with anything physical?

Descartes to Elisabeth, 28 June 1643

Descartes’s reply is widely regarded as one of his least successful philosophical moments. He acknowledges the difficulty and appeals to a third “primitive notion” — the union of mind and body — which he says cannot be understood through either the concept of mind alone or the concept of body alone, but only through lived experience. We know that mind and body interact because we experience it every day: our decisions move our limbs, and bodily sensations produce thoughts.

Elisabeth finds this unsatisfying. Descartes seems to be saying: “Don’t try to understand how mind-body interaction works; just notice that it does.” This amounts to abandoning the philosophical project of explanation.

Elisabeth to Descartes, 1 July 1643

Elisabeth presses further. She notes that appealing to everyday experience does not solve the philosophical problem — it merely restates it. She also raises the possibility that the soul might, after all, have some kind of extension, which would make interaction intelligible but would undermine Descartes’s entire dualist framework.

Why Elisabeth Matters

Elisabeth’s critique is remarkable for several reasons:

1. She identified the central problem of Cartesian dualism more clearly than anyone else in the seventeenth century. The mind-body problem, as she formulated it, remains one of the central problems of philosophy of mind today.

2. She did not merely raise an objection — she offered a constructive alternative. By suggesting that the soul might have extension, she anticipated later philosophical positions (such as property dualism and physicalism) that try to bridge the mind-body gap.

3. She held Descartes to his own standards. Descartes claimed to accept only what could be clearly and distinctly perceived. Elisabeth showed that his account of mind-body interaction failed this very test.

4. She expanded the philosophical agenda. In later letters, Elisabeth and Descartes discussed the passions, the nature of virtue, the role of the body in emotional life, and the relationship between health and happiness — topics Descartes might not have explored as deeply without her prompting.

4.5 Borges: The Library of Babel

Jorge Luis Borges (1899–1986) was an Argentine writer whose short stories explore philosophical themes with extraordinary imaginative power. “The Library of Babel” (1941) is often assigned alongside the epistemology unit because it dramatizes the limits of knowledge in a memorable way.

The Story

The Library of Babel is a universe consisting entirely of hexagonal rooms filled with books. The books contain every possible combination of letters, spaces, and punctuation marks. This means the Library contains every book that could ever be written — every true statement, every false statement, every meaningful sentence, and every meaningless string of characters.

The Epistemological Problem

The Library contains all knowledge, yet its inhabitants cannot find it. The overwhelming majority of books are gibberish. Even the books that contain true and meaningful statements cannot be reliably identified as such, because for every true book there are countless nearly identical books containing subtle errors. The librarians wander through an infinity of information with no way to distinguish truth from falsehood.

4.6 Locke: Empiricism and the Origin of Ideas

The Thinker

John Locke (1632–1704) was an English philosopher and physician, widely regarded as the founder of empiricism (经验主义) — the view that all knowledge comes from sensory experience. His An Essay Concerning Human Understanding (1689) is one of the foundational texts of modern philosophy.

Against Innate Ideas

Locke begins Book II of the Essay by arguing against the rationalist view (held by Descartes and others) that some ideas are innate (先天的) — present in the mind from birth. Locke’s famous counter-image is the tabula rasa (白板): the mind at birth is a “blank slate,” a “white paper, void of all characters.” All ideas enter the mind through experience.

Two Sources of Ideas

Locke identifies two sources from which all our ideas derive:

1. Sensation (感觉): Ideas produced by external objects acting on our senses — colors, sounds, textures, tastes, smells.
2. Reflection (反省): Ideas produced by the mind’s awareness of its own operations — thinking, doubting, believing, willing.

Simple and Complex Ideas

Simple ideas (简单观念) are the basic building blocks of thought. They are received passively through sensation or reflection and cannot be broken down further (e.g., the idea of “red,” “sweet,” or “cold”).

Complex ideas (复杂观念) are constructed by the mind from simple ideas through combination, comparison, or abstraction (e.g., the idea of “gold” combines the simple ideas of yellow color, certain weight, malleability, etc.).

Primary and Secondary Qualities

In Book II, Chapter 8 (paragraphs 7–22), Locke draws one of the most influential distinctions in the history of philosophy:

Philosophical Significance

Locke’s distinction raises a troubling question: if secondary qualities exist only in the mind, how much of what we experience is really “out there” in the world? Locke maintains that primary qualities give us genuine knowledge of external reality, but secondary qualities are, in a sense, mental constructions. This opens a door that Berkeley will push wide open.

4.7 Berkeley: Idealism and “To Be Is to Be Perceived”

The Thinker

George Berkeley (1685–1753) was an Anglo-Irish philosopher and Anglican bishop. He is the most famous proponent of idealism (唯心主义/观念论) — the view that reality consists entirely of minds and their ideas. His major work is A Treatise Concerning the Principles of Human Knowledge (1710).

Berkeley’s Radical Move

Berkeley accepts Locke’s empiricism but pushes it to a startling conclusion. If all our knowledge comes from sensory experience, and if secondary qualities (color, sound, taste) exist only in the mind, then why should we believe that primary qualities (shape, size, motion) are any different? After all, we access primary qualities through the same senses that produce secondary qualities. Shape is perceived through sight and touch, just as color is perceived through sight.

Berkeley concludes that all qualities are mind-dependent. There is no “material substance” lurking behind our perceptions. The physical world, as we know it, consists entirely of ideas perceived by minds.

Berkeley’s Arguments

1. The Impossibility of Conceiving Unperceived Objects. Try to conceive of a tree that no one is perceiving. Berkeley argues that in the very act of conceiving it, you are perceiving it (in imagination). You can never step outside perception to verify that objects exist independently of it.

2. The Likeness Principle. An idea can only resemble another idea. If our ideas of primary qualities are supposed to “resemble” properties of material objects, what does that mean? Material objects, by definition, are not ideas. How can a non-mental thing resemble a mental thing?

3. Against Material Substance. Locke posited “material substance” as the unknown “something” that supports the qualities we perceive. Berkeley argues that this notion is incoherent — we have no idea of what “substance” is apart from the qualities we perceive, so the concept is empty.

The Role of God

Berkeley avoids solipsism (the view that only my mind exists) by invoking God. Physical objects continue to exist when no human perceives them because God always perceives everything. The regularity and order of our experiences is explained by God’s continuous perception of the world.

Chapter 5: Philosophy of Science

5.1 What Makes Science Scientific?

The philosophy of science asks a question that might seem odd at first: what distinguishes science from non-science? We all have an intuitive sense that physics is a science and astrology is not — but can we articulate why? This question is known as the demarcation problem (划界问题). This chapter examines three influential answers: Popper’s falsificationism, Kuhn’s paradigm theory, and Longino’s social epistemology.

5.2 Popper: Falsificationism

The Thinker

Karl Popper (1902–1994) was an Austrian-British philosopher of science. His central concern was distinguishing genuine science from pseudoscience. His key works include The Logic of Scientific Discovery (1934/1959) and Conjectures and Refutations (1963).

The Problem with Verification

The commonsense view of science is that scientists gather observations and use them to verify (confirm) their theories. Popper rejected this view. He pointed out a logical asymmetry between verification and falsification (证伪):

• No finite number of observations can verify a universal claim. (You can observe a million white swans without proving that all swans are white.)
• A single observation can falsify a universal claim. (One black swan disproves “all swans are white.”)

Popper’s Demarcation Criterion

Popper uses falsifiability as the line between science and non-science:

• Scientific theories make risky predictions that could be refuted. Einstein’s general relativity predicted that light bends around massive objects — a prediction that could have been proven wrong (but was confirmed in 1919).
• Pseudoscientific theories are formulated so vaguely that no observation could ever refute them. Popper argued that Freudian psychoanalysis and Marxist theories of history were unfalsifiable because their adherents could always reinterpret evidence to fit the theory.

The Method of Conjecture and Refutation

Popper proposed that science advances not by accumulating confirmations but by bold conjectures followed by rigorous attempts at refutation. Scientists should try their hardest to disprove their own theories. A theory that survives many sincere attempts at refutation is well-corroborated (though never finally proven).

Criticisms of Popper

1. The Duhem-Quine problem. When an experiment produces unexpected results, scientists cannot be sure which part of their theory is wrong. Hypotheses are never tested in isolation — they depend on auxiliary assumptions (about instruments, background conditions, etc.). A failed prediction might mean the main theory is wrong, or it might mean one of the auxiliary assumptions is wrong.

2. Scientists do not behave as Popper prescribes. Historians of science (notably Kuhn) have shown that scientists rarely abandon their theories after a single falsification. They often work to modify or repair theories rather than discard them.

5.3 Quine and Underdetermination

W. V. O. Quine (1908–2000) extended the Duhem problem into a broader philosophical thesis. Underdetermination (不充分决定性) is the idea that our evidence never uniquely determines which theory is correct. For any body of evidence, there are always multiple theories that are equally compatible with it.

Quine argued that our theories face the “tribunal of experience” not individually but as a whole. When evidence conflicts with our beliefs, we have a choice about which belief to revise. This means that theory choice always involves an element of decision that goes beyond the evidence itself — a theme that Longino will develop in a social direction.

5.4 Kuhn: Paradigms and Scientific Revolutions

The Thinker

Thomas Kuhn (1922–1996) was an American physicist and philosopher of science. His book The Structure of Scientific Revolutions (1962) transformed the way we think about the history and nature of science.

Normal Science and Paradigms

Kuhn introduces the concept of a paradigm (范式):

During periods of normal science (常规科学), scientists work within an established paradigm. Normal science is not about making revolutionary discoveries; it is puzzle-solving (解谜). Scientists apply the paradigm’s methods to solve problems that the paradigm itself defines. The paradigm is not questioned; it is assumed.

Anomalies and Crisis

Sometimes, normal science produces results that do not fit the paradigm — anomalies (反常). Initially, anomalies are set aside or explained away. But if anomalies accumulate and resist resolution, the scientific community enters a period of crisis (危机). Confidence in the paradigm erodes, and scientists begin to entertain radically new ideas.

Scientific Revolutions

A scientific revolution (科学革命) occurs when a new paradigm replaces the old one. This is not a smooth, cumulative process. The new paradigm does not simply add to the old one; it replaces it, often changing the fundamental concepts, methods, and standards of the field.

Incommensurability

Kuhn’s most controversial claim is that successive paradigms are incommensurable (不可通约的) — they cannot be directly compared using a neutral standard. Scientists working in different paradigms may use the same words (e.g., “mass”) but mean different things by them. There is no paradigm-independent standpoint from which to judge which paradigm is “better.”

5.5 Longino: The Social Dimensions of Scientific Knowledge

The Thinker

Helen Longino (b. 1944) is an American philosopher of science at Stanford University. Her work builds on the insights of Kuhn and Quine while adding a distinctively social and feminist dimension.

Science as Social Knowledge

In Science as Social Knowledge (1990), Longino argues that scientific knowledge is not the product of isolated individual minds but of social communities. Evidence does not interpret itself — scientists must decide what the evidence means, and these decisions are influenced by background assumptions that often reflect social values.

Objectivity as Social

Longino redefines objectivity (客观性). On her view, objectivity is not a property of individual scientists (their personal detachment or impartiality) but a property of scientific communities. A community produces objective knowledge to the extent that it meets certain social conditions:

1. Public venues for criticism. There must be recognized forums (journals, conferences) where criticism can be expressed.
2. Uptake of criticism. The community must actually respond to criticism — not just allow it but engage with it.
3. Shared standards. The community must have publicly recognized standards for evaluating theories and evidence.
4. Tempered equality of intellectual authority. No perspective should be dismissed merely because of the social identity of the person offering it. Diverse perspectives strengthen the critical process.

Why Diversity Matters for Science

Longino argues that homogeneous scientific communities are more likely to share the same unexamined background assumptions. If everyone in a research group comes from the same social background, they are less likely to notice or challenge the assumptions embedded in their work. Diversity of perspectives is not just a matter of fairness — it is an epistemic resource that improves the quality of science.

Chapter 6: Free Will and Determinism

6.1 The Problem of Free Will

Do we have free will (自由意志)? This question is one of the oldest and most deeply felt in philosophy. It touches everything from morality and law to personal identity and the meaning of life. If our actions are determined by prior causes — whether physical laws, divine decree, or fate — then in what sense are we responsible for what we do?

Three main positions define the landscape:

• Hard determinism (硬决定论): Determinism is true, and therefore free will is an illusion.
• Libertarianism (自由意志论, not to be confused with the political philosophy): Free will is real, and therefore determinism must be false — at least for human actions.
• Compatibilism (相容论): Free will and determinism are compatible. We can be free even in a deterministic universe, as long as our actions flow from our own desires and deliberations rather than from external compulsion.

6.2 Aristotle on Voluntary Action

Aristotle addresses the question of voluntary action in Book III of the Nicomachean Ethics. While he does not use the modern term “free will,” he provides a foundational analysis of what it means for an action to be voluntary.

Voluntary vs. Involuntary

Aristotle distinguishes between:

• Voluntary actions (自愿行为): Actions whose “moving principle” is in the agent — the agent knows the circumstances and chooses to act. These actions are within the agent’s power to do or not do.
• Involuntary actions (非自愿行为): Actions performed under compulsion (the moving principle is outside the agent) or ignorance (the agent does not know the relevant circumstances).

Deliberation and Choice

For Aristotle, mature human beings make choices (选择, prohairesis) after deliberating (审思) about the available means to their ends. We do not deliberate about things we cannot control (the weather, the past) but only about things that are “in our power.” Choice is a product of both desire and reason.

Character Formation

Crucially, Aristotle links voluntary action to character (品格). Our characters are formed by our habits, and our habits are formed by our repeated actions. A person who repeatedly chooses to act courageously becomes courageous; a person who repeatedly chooses to act cowardly becomes cowardly. We are responsible for our characters because we shaped them through our voluntary choices.

6.3 Sophocles: Oedipus Rex and the Problem of Fate

The Story

Sophocles’ Oedipus Rex (c. 429 BCE) tells the story of Oedipus, King of Thebes, who discovers that he has unknowingly fulfilled a terrible prophecy: he has killed his father and married his mother. Despite all his efforts to avoid this fate, every action he takes leads him closer to it.

Fate vs. Free Will in Oedipus

The play dramatizes the tension between fate (命运) and human agency. Oedipus acts freely in the ordinary sense — he makes decisions, investigates, pursues the truth. Yet the outcome was determined before he was born. His freedom seems real in the moment but illusory in the larger scheme.

Scholars have debated Oedipus’s agency:

• The fatalist reading: Oedipus never had a chance. The prophecy was fixed; his “choices” were merely the mechanisms by which fate unfolded. This supports fatalism (宿命论) — the view that what will happen will happen regardless of what we do.
• The free agent reading: Oedipus was free in one crucial respect: he was free to seek the truth or not. The prophecy determined the events, but Oedipus’s relentless investigation — his refusal to stop asking questions — was his own choice. As Bernard Knox argued, “Oedipus did have one freedom: he was free to find out or not to find out the truth.”
• Oedipus’s own view: At the end of the play, Oedipus says that his terrible deeds were fated, but that he alone chose to blind himself. Fate determined what happened to him; how he responded to it was his own decision.

6.4 Ted Chiang: “Story of Your Life” and Compatibilism

The Story

Ted Chiang’s “Story of Your Life” (1998) — the basis for the film Arrival (2016) — is a science fiction novella in which a linguist named Louise Banks learns the language of an alien species called the Heptapods. As she becomes fluent in their language, she begins to perceive time the way they do: not as a sequence of moments unfolding from past to future but as a block (块状宇宙) in which past, present, and future all coexist simultaneously.

The Philosophical Core

As Louise gains knowledge of the future — including the birth and death of her daughter — she faces the question at the heart of the free will debate: If you know what is going to happen, can you keep it from happening? And if you cannot, are you still free?

Chiang’s Compatibilism

Chiang has described himself as a compatibilist. In interviews, he has said that “Story of Your Life” explores whether there can be “a robust concept of free will that’s fully consistent with a deterministic universe — not just an illusion of free will, but actually something that’s somehow consistent with a fully deterministic universe.”

Louise knows the future, yet she embraces it. She chooses to have her daughter, knowing the joy and the grief that will follow. Her foreknowledge does not feel like a prison; it feels like a different mode of engagement with life. Rather than choosing blindly from an open future, she acts with full awareness, and this awareness is itself a form of freedom.

6.5 Pulling It Together: What Is Freedom?

The three perspectives explored in this chapter — Aristotle, Sophocles, and Chiang — offer different but complementary insights:

Conclusion: The Ongoing Conversation

This course has traced a path from Russell’s call to philosophical wonder through the foundations of logical reasoning, Aristotle’s common-sense metaphysics, the epistemological journey from Teresa of Avila to Berkeley, the nature and social dimensions of science, and the ancient puzzle of free will. The thinkers studied here span more than two millennia — from Aristotle and Sophocles to Ted Chiang — yet they are united by a shared commitment to asking hard questions honestly.

Philosophy does not end with this course. As Russell reminded us, its value lies not in final answers but in the enlargement of mind that comes from the pursuit. The questions raised here — What can I know? What is real? Am I free? — are not problems to be solved and set aside. They are invitations to a lifetime of thinking, and they are open to everyone willing to enter the conversation.