Theories of Knowledge: How to Think about What You Know

Theories of Knowledge: How to Think about What You Know
Course Trailer
Philosophy and Transformative Experiences
1: Philosophy and Transformative Experiences

What do philosophical “theories of knowledge” have to do with everyday life? If you believe the field of epistemology is esoteric and abstract, you’ll be surprised by how fundamental it is to everyday life. In this opening lecture, reflect on how we make “transformative” experiences—and why common sense might lead us astray.

29 min
Knowledge, Truth, and Belief
2: Knowledge, Truth, and Belief

Philosophers have been ruminating on the nature of knowledge for thousands of years. Using Plato as your guide, investigate the relationship between “knowledge,” “truth,” and “belief.” Professor Shieber brings in contemporary psychology and what we know about child development to show how we come to know what we know.

28 min
Foundationalism: Descartes’s Evil Demon
3: Foundationalism: Descartes’s Evil Demon

We’re all familiar with Descartes’s cogito, ergo sum, or “I think, therefore I am.” Delve into this powerful analysis of reality to discover what Descartes meant. As you’ll learn, he was trying to develop an infallible explanation for his knowledge of the world, which led him deep inside his own mind.

28 min
The Coherence Theory of Knowledge
4: The Coherence Theory of Knowledge

Turn from Descartes’s theory of infallible knowledge to fallible yet still internal theories of reality. The most prominent theory is coherentism, a framework for understanding the world in terms of logical cohesion and consistency. While this theory has much to offer, you’ll also wrestle with several key challenges.

31 min
Externalist Theories of Knowledge
5: Externalist Theories of Knowledge

Not all theories of knowledge rely on internal justification. Here, you will explore several 20th-century approaches to knowledge that don’t require that justification is internally accessible. Consider how to gauge beliefs in terms of external consistency, accuracy, reliability, and validity.

29 min
Problems with Self-Knowledge
6: Problems with Self-Knowledge

Given all this talk of beliefs and external reality, surely it’s safe to say we at least understand ourselves, right? Traditional, Cartesian epistemology may consider self-knowledge the foundation of all other knowledge, but as current research in psychology, biology, and neuroscience shows, our self-knowledge is far from complete or even accurate.

29 min
Does Sense Perception Support Knowledge?
7: Does Sense Perception Support Knowledge?

One of the most significant sources of knowledge comes from sense perception—what we see, hear, smell, and experience of the world. Yet our common-sense way of thinking about sense perception is misleading at best. In this first of two lectures on perception, unpack the role of our senses in justifying beliefs about the world.

30 min
Perception: Foundationalism and Externalism
8: Perception: Foundationalism and Externalism

Continue your study of sense perception with a look at what it implies about the internalist and externalist theories you have studied so far. After examining several problems with internalist foundationalism, Professor Shieber explores how cognitive psychology supports an externalist view of knowledge.

28 min
The Importance of Memory for Knowledge
9: The Importance of Memory for Knowledge

Memory plays a crucial role in knowledge because all of our perceptions are impermanent and fleeting. Here, you will examine the nature of memory. Are memories stored experiences in the mind, or are they past events themselves? And does memory merely preserve belief, or can you gain new knowledge from your memories?

28 min
Confabulations and False Memories
10: Confabulations and False Memories

One of the most intriguing aspects of memory is just how fallible it is as a guide to reality. In this lecture, you will turn to how memory fits into the internalist and externalist theories of knowledge. False memories, confabulations, source theories, and forgotten evidence show just how tricky memory really is.

28 min
The Extended Mind
11: The Extended Mind

We are quickly approaching a future of augmented reality, simulated consciousness, brain implants, and more. These brain enhancements raise a number of philosophical questions: What counts as your mind? And is an enhanced brain a better brain? Consider the role of smart phones and photographs in preserving memory.

28 min
Do We Have Innate Knowledge?
12: Do We Have Innate Knowledge?

Step back to one of the Enlightenment’s most captivating debates: Do we know the world through our own minds (as Descartes argued) or through empirical evidence (as Locke and Hume argued)? After unpacking this debate, see how Kant came to the rescue to distinguish between a priori and a posteriori knowledge.

29 min
How Deduction Contributes to Knowledge
13: How Deduction Contributes to Knowledge

Much of our belief system stems from things we have not experienced directly; rather, we infer much of our knowledge through the processes of logical reasoning. Here, tackle the role of deduction, in which inference stems from the logical relationship of a series of steps. Consider syllogisms, “if-then” arguments, and other deductive procedures.

29 min
Hume’s Attack on Induction
14: Hume’s Attack on Induction

Deduction and induction are the two types of logical inference. In this first of two explorations of induction, you will examine the reliability and usefulness of induction. You’ll start with David Hume’s challenge to induction to see whether it can be used to generate knowledge at all. And even if knowledge comes from inductive inference, are humans any good at it?

28 min
The Raven Paradox and New Riddle of Induction
15: The Raven Paradox and New Riddle of Induction

Continue your tour of induction by looking at a few logical puzzles. There are no easy answers to the raven paradox or the new riddle of induction, but picking apart these challenges can offer valuable lessons about inductive inference. Revisit Hume’s attack, and reflect on how Bayes’s theorem of probability applies to inductive reasoning.

28 min
Know-How versus Propositional Knowledge
16: Know-How versus Propositional Knowledge

So far, this course has tackled “propositional knowledge”—or knowledge that X is true. But knowledge-that isn’t the only kind of knowledge. Although philosophers didn’t think much about knowledge-how (know-how) until recently, it has much to teach us—especially about internalist and externalist theories of knowledge.

30 min
Knowledge Derived from Testimony
17: Knowledge Derived from Testimony

Sensory perception, memory, self-awareness, and logical inference are all personal sources of knowledge, but much of our knowledge comes from consulting others’ expertise. Discover the breadth of knowledge that comes from testimony, and find out what perils exist in relying on the word of others.

28 min
Social Psychology and Source Monitoring
18: Social Psychology and Source Monitoring

To evaluate knowledge that comes from testimony, you might think we analyze the trustworthiness of the source and weigh our beliefs accordingly. But as social psychology tells us and you will see here, we are very bad at spotting liars, and we tend to accept testimony without consciously monitoring the source of the information.

29 min
Testimony through Social Networks
19: Testimony through Social Networks

Social networks play a powerful role in how we acquire knowledge from others. Here, explore the nature of our social networks—how many close friends we tend to have, and how many people are in our wider social network—and then see how our networks provide us information, and how reliable the information is.

28 min
The Reliability of Scientific Testimony
20: The Reliability of Scientific Testimony

Previously, you discovered the “social externalist” theory of testimony. Examples from the scientific world provide evidence for this view of ensuring accurate testimony. Reflect on several scientific achievements made possible by “socially distributed cognitive processes”—processes where the sum is greater than the individual players.

29 min
Testimony in the Media
21: Testimony in the Media

The media is a great example of a socially distributed process—but how do we know the information is reliable and accurate? Go inside the world of media fact-checking and how our media consumption impacts our knowledge. Consider the challenge of ensuring accuracy in the age of “click-bait.”

28 min
Pragmatic and Moral Encroachment
22: Pragmatic and Moral Encroachment

Much of this course has focused on the truth-likelihood of knowledge, without focusing on the particular interests of the knower. In this lecture, survey two key challenges to this approach: First, do your practical interests impact whether you have knowledge? Second, do your moral concerns impact whether you have knowledge?

27 min
Radical Skepticism: The Brain in a Vat
23: Radical Skepticism: The Brain in a Vat

Return to the beginning, in which you studied Descartes’s radical skepticism. While there are many problems with Descartes’s theory of knowledge, his fundamental skepticism is tough to reckon with. How do we know we are not just a brain in a vat, à la The Matrix? Delve into several arguments against this scenario.

28 min
The Future of Epistemology
24: The Future of Epistemology

Epistemology is an old field, but in the 21st century there has been an explosion of new ideas, approaches, and applications. Conclude the course with a look at the future of the field, including “formal epistemology,” “epistemic injustice,” and the potential integration of externalist, foundationalist, and coherentist approaches to knowledge.

37 min
Joseph H. Shieber

 The study of knowledge is as old as philosophy itself.


Brown University


Lafayette College

About Joseph H. Shieber

Joseph H. Shieber is an Associate Professor in the Department of Philosophy at Lafayette College, where he has taught since 2003. Before arriving at Lafayette, he taught philosophy at Brown University, Connecticut College, and the Massachusetts Institute of Technology. Dr. Shieber earned a BA in Literature from Yale University, studied mathematics and philosophy at the Freie Universität Berlin, and earned AM and PhD degrees in Philosophy from Brown University.

Dr. Shieber has published numerous articles in epistemology, philosophy of language, and the history of modern philosophy in some of the top journals in the field of philosophy. He is also the author of Testimony: A Philosophical Introduction as well as a monthly Monday columnist for 3 Quarks Daily (

Dr. Shieber is a recipient of the Thomas Roy and Lura Forrest Jones Faculty Lecture Award in recognition of excellence in teaching and scholarship from Lafayette College. He regularly teaches courses in theory of knowledge, philosophy of language, history of 20th-century philosophy, logic, and metaphysics as well as a first-year seminar on propaganda.

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