Stephen Read: Liar Paradox | WSB #41

May 22, 2018

"This sentence is false". Is that sentence true or false? If it's true, then what it says must hold; but what it says is that it's false, so it must be false. But if it's false, then what it says must not hold; but what it says is that it's false, so it must not be false. But if it's not false, it must be true. So if the sentence is true, it is false, and if it is false, it is true. The sentence, therefore, seems to be both true and false, which seems absurd.

Philosopher and logician Stephen Read is one of the preeminent scholars on this "liar paradox". He is known, in large part, for rediscovering and defending a long forgotten solution to the paradox first proposed by the medieval philosopher Thomas Bradwardine. In this first half of our conversation, Read covers the paradox's rich and influential history. It was first discovered, in its full form, in the 4th century BCE by Eubulides (who also first set down the sorites paradox). It became a central problem in the 20th century via its association with Russell's Paradox, a major problem in the foundations of mathematics. Later in the century, two thinkers - Alfred Tarski and Saul Kripke - proposed monumentally influential theories of language and truth motivated, largely, by the paradox. But even after their contributions, the consensus is that the paradox remains unsolved. Quite a few new solutions have been suggested in the decades since Kripke's 1975 proposal. Among the more influential is Stephen Read's revival of the Bradwardine solution, which will the subject of part 2 of this interview.

Next week: Stephen Read: Medieval Solutions to the Liar

Visit http://williamnava.com or more info!

I've discussed the Liar briefly before, in both part 1 and part 2 of my interview with Graham Priest.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

Stephen Read (homepage)
"Liar Paradox" (Internet Encyclopedia of Philosophy)
"Tarski's Truth Definitions" (Stanford Encyclopedia of Philosophy)
"Outline of a Theory of Truth" (Saul Kripke)

Topics discussed:

0:19 - Intro to Stephen Read
4:24 - What is the Liar Paradox?
6:33 - The Greeks on the Liar
11:06 - Frege, Cantor's Paradox, and Russell's Paradox
18:24 - Tarski's solution
21:55 - Natural language, formal languages, semantics, and the T-schema
32:03 - Shortcomings of Tarski's solution
36:12 - Kripke's solution

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T.K. Coleman: Sacramental Christianity | WSB #40

May 15, 2018

We often think of religion as being centered around a series of beliefs. To be Christian, I must believe in the veracity of the Bible as a literal account of historical events. Doubt, then, is a problem to be dealt with. Understandable for a while, perhaps, but something which must be overcome in order to be in good standing with the faith.

T.K. Coleman offers an alternative approach to Christianity: a Sacramental approach, which focuses not on the belief requirement, but on the personal and transformative aspect of interacting with the Bible and with the faith. To be a Christian is not to have a set of beliefs, but to seek transformative experiences of intimacy with the divine. The literal truth of the Bible is, to an extent, secondary. Doubt becomes an inescapable part of interacting with the faith as a Sacrament. In the end, some stories may well be literally true, says Coleman; others best seen as metaphorical. For the second half of the interview, we discuss at length the metaphysical and epistemic issues surrounding belief in these stories, and in miracles broadly.

Next week: Stephen Read: Liar Paradox

Visit http://williamnava.com or more info!

I've discussed Christianity before, in my interview with professor Jim Slagle.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

T.K. Coleman (homepage)
Praxis

Topics discussed:

0:19 - Intro to TK Coleman
4:30 - TK's childhood with Christianity
15:11 - The importance of philosophy
27:53 - Doubt
39:55 - Sacramental Christianity
55:33 - Literal veracity of Biblical events
1:07:37 - Metaphorical v. literal interpretations
1:21:40 - Belief in miracles
1:28:18 - Personal experiences and the role of evidence
2:04:05 - Religious pluralism
2:11:40 - Conclusion

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David Papineau: Mary’s Room | WSB #39

May 8, 2018

Mary has lived her entire life in a black and white room. In that room, she learned everything there is to know about the neurophysiology of perception. She knows everything that happens in the brain when a person sees a blue sky. One day, Mary leaves the black and white room and sees the blue sky. Has Mary learned something new?

Frank Jackson posed this famous thought experiment as a challenge to physicalists, such as David Papineau, who argue that qualitative experiences are identical to brain states. If this is really so, the argument goes, Mary isn't learning anything new, since she already knew everything about the relevant brain states. But she does seem to learn something new: what it's actually like to see blue. In this interview, Papineau addresses this challenge and explains why he thinks that, despite our intuitions to the contrary, qualitative experiences are simply neural states under a different description.

Be sure to listen to the first half of this interview, where David explains Russellian monism and the causal argument.

Next week: T.K. Coleman: Sacramental Christianity

Visit http://williamnava.com or more info!

If you're interested in Mary's Room and qualia, check out this interview with David Rosenthal.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

David Papineau (homepage)
"
Naturalism and Physicalism" (David Papineau)
"Epiphenomenal Qualia" (Frank Jackson)

Topics discussed:

1:20 - Mary's room
3:21 - Mary discovers a new concept for the same thing
6:46 - Phenomenal concepts as revelatory
10:37 - Russellian monism again
17:46 - Being like something
19:47 - Ontology of different concepts
32:36 - Aspect of the brain state?

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David Papineau: Physicalism | WSB #38

May 1, 2018

Most contemporary philosophers call themselves "naturalists" or "physicalists". But what do these labels really mean? What do they commit us to?

Philosopher David Papineau first puts it negatively: physicalists deny the existence of the supernatural, or of "anything spooky". More specifically, only those things that play a causal role in the spatiotemporal world exist. And, modern physics tells us, only the physical plays such a causal role. For this reason, "abstract objects" that don't themselves affect the physical world, such as numbers, should not be said to exist.

For much of the interview, Papineau runs through a "causal argument" to show that consciousness is physical. The argument begins with the premise that mental states have physical effects (for example, my experience of pain causes me to cry out). It also assumes that physical effects have only physical causes and that events aren't systematically overdetermined (caused by two things at once, like a man killed by a gunshot and a bolt of lightning at once). If this is all true, it follows that mental states must themselves be physical. Papineau runs through possible ways out of this causal argument, including epiphenomenalism. In the process, he runs through a brief history of modern physics and how we came to discover that all physical effects have physical causes. He concludes with an exploration of panpsychism and "Russellian monism", views that attempt to accept the causal argument but deny that consciousness is therefore strictly physical.

Next week: David Papineau: Mary's Room

Visit http://williamnava.com or more info!

Interested in ontology? Check out my interview with Amie Thomasson about metaontology.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

David Papineau (homepage)
"
Naturalism and Physicalism" (David Papineau)

Topics discussed:

0:19: Introduction to David Papineau (sports and philosophy, metaphilosophy)
5:20 - What is naturalism?
15:15 - Do "abstract objects" exist?
19:56 - Causal argument for physicalism
26:49 - Ways out: epiphenomenalism and overdetermination
30:59 - Physical causes for physical effects: a short history of modern physics
44:39 - Quantum mechanics
48:54 - Panpsychism and Russellian monism

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Peter Klein: What Is Knowledge? (Gettier Problem) | WSB #37

April 24, 2018

What is knowledge?

For some time, the answer to this perennial question was thought by many to be "justified true belief". If I believe X to be true, I have good reason for believing X to be true, and X really is true, then I know X. In 1963, Edmund Gettier published a now legendary three-page paper titled "Is Justified True Belief Knowledge?" in which he gave two examples of justified true belief that did not constitute knowledge. Since then, epistemologists have mostly agreed that there's some extra ingredient requisite for knowledge but have disagreed about what it is. After drawing out Gettier's examples, Peter Klein explains that there are two major camps. The first he calls etiology of belief: theories in which the extra ingredient has to do with how the belief was attained. Reliabilists, for example, argue that a justified true belief counts as knowledge if the belief is arrived at via a method that reliably delivers accurate beliefs. Klein belongs to the second camp: quality of evidence theories, which have to do with the strength of the justification, not the cause of the belief. Klein defends his own preferred quality of evidence theory: defeasibility theory, which involves the existence or absence of "defeaters" for the justification.

Next week: David Papineau: Physicalism

Visit http://williamnava.com or more info!

Interested in knowledge? You may be interested in Alvin Plantinga's epistemology, which I discussed with professor Jim Slagle.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

Explaining Knowledge: New Essays on the Gettier Problem (ed. Claudio de Almedia, Rodrigo Borges, Peter Klein)
"Is Justified True Belief Knowledge?" (Edmund Gettier)

Topics discussed:

0:53 - Introducing the Gettier problem (fallibilism and closure)
5:14 - Gettier's first example: Smith and Jones
8:43 - Gettier's second example: Jones and Brown
13:18 - Warrant
15:37 - Etiology of belief solutions: tracking, virtue, reliabilism
20:52 - Causes of belief
28:52 - Peter Unger on psychological certainty
33:22 - Defeasibility theory
46:41 - Argument against closure

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Peter Klein: Infinitism and Pyrrhonism | WSB #36

April 17, 2018

Suppose you know X. How do you know? Maybe you know because of Y. How do you know Y? Maybe the answer is Z. How do you know Z?

This is the regress problem of knowledge, also called the Agrippan trilemma and the Münchhausen trilemma. It is based on the supposition that if we claim to know something, we must have a reason for it and that reason must itself be something that we know. This leaves open four possible solutions. One is skepticism, the belief that we have no knowledge. The most common is foundationalism, which posits certain basic facts that require no external reasons to be justified. Another option is coherentism, which solves the problem via a kind of circular reasoning or justification loop. And finally, there is infinitism, the view that there is no end to the regress. For any chain of justification, the final member of the chain will always be unjustified, and it is always possible to go looking for further reasons of reasons of reasons. As infinitist Peter Klein puts it, knowledge is never "settled". Even so, says Klein, it is still possible to have knowledge. In this interview, Klein first argues why he thinks coherentism, foundationalism, and a certain kind of skepticism all fail. He then explains his own account of justification, as "something that we do", and how it makes the infinitist picture look more plausible than it first seems. Along the way, he recounts the framing of the problem by Sextus Empiricus in his book Outline of Pyrrhonism. Klein argues that the ancient Greek Pyrrhonians, though they called themselves skeptics, were really infinitists.

Next week: Peter Klein: What Is Knowledge? (The Gettier Problem)

Visit http://williamnava.com or more info!

Interested in regress problems? I discussed them, including the knowledge regress, in my interview with Graham Priest. I also discussed the Agrippan trilemma in my discussion with Jim Slagle.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

Ad Infinitum: New Essays on Epistemological Infinitism (ed. Peter Klein and Peter Turri)
"The Failures of Dogmatism and a New Pyrrhonism" (Peter Klein)
Outlines of Pyrrhonism (Sextus Empiricus)

Topics discussed:

0:19 - Introduction to Peter Klein
1:21 - The regress problem in epistemology (the Agrippan trilemma)
6:58 - Contemporary coherentism
15:10 - Sexus Empircus and the five modes
21:28 - Problems with foundationalism
30:42 - Mechanics of justification
37:18 - Pyrrhonians as infinitists
44:43 - Psychological certainty
46:25 - How do we find reasons?

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Bryan Caplan: Non-State Legal Systems | WSB #35

April 10, 2018

Does the law need to be provided by the state?

Economist Bryan Caplan breaks down the law into three components: rule formation, arbitration, and enforcement. For all three, he provides examples of how these are already provided without the state in many contexts. He also explains the theoretical reasons we shouldn't be surprised to find law provided without the state, usually better than the state does. He goes on to speculate how the law could be provided if there were no state at all. Finally, he considers two common objections: that law without the state leads to chaos, and that providers of legal services in a world without the state will inevitably collude and come together to form a new state.

Next week: Peter Klein: Infinitism and Pyrrhonism

Visit http://williamnava.com or more info!

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

The Case against Education (Bryan Caplan)
Bryan Caplan (homepage)
"The Economics of Non-State Legal Systems" Part 1, Part 2, Part 3 (Bryan Caplan)
"Law as a Public Good: The Economics of Anarchy" (Tyler Cowen)
"Outline of a Critique of Tyler Cowen's 'Law as a Public Good'" (Bryan Caplan)
"Networks, Law, and the Paradox of Cooperation" (Bryan Caplan, Edward Stringham)
"Adjudication as a Private Good" (Richard Posner, William Landes)

Topics discussed:

1:14 - Non-state law that already exists
2:23 - Innovation in the creation of new rules (copyright)
5:11 - Private enforcement of law: private security, ostracism, bonds
7:32 - Private arbitration and private rule formation
9:13 - Benefits of competition
13:54 - Expanding role of contracts
19:03 - Private law without contracts
20:24 - Law without any government
27:34 - Collusion objection and economies of scale
29:27 - Tyler Cowen's collusion argument from network industries

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Bryan Caplan: The Case against Education | WSB #34

April 3, 2018

Why do students go to school? The usual answer is to learn. But if this is true, why do students rejoice at canceled class? Why do they prefer an easy "A" instructor over a difficult one who has more to offer? Why don't they just sit in on classes for free, which you can do at many of the best schools? And why is the final year of school so much more lucrative than other years, given that we don't usually learn more that year?

These problems and others fall into place when we consider that we go to school more for the degree than for the education. The main purpose of education is to send a signal to employers, says economist Bryan Caplan. Employers pay more for college-educated employees not because what they learned in school was itself useful, but because the fact that they got the degree demonstrates that they must be generally smart, disciplined, and conformist. This makes little difference to the individual - you should still go to school and send that signal. But for society, this makes education a bad deal; status, unlike learning, is zero-sum, making much of the education system a waste of resources. In this interview, Caplan explains the signaling model in more detail, addresses objections, and predicts what would happen if his prescriptions were followed.

Next week: Bryan Caplan: Non-State Legal Systems

Visit http://williamnava.com or more info!

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:

The Case against Education (Bryan Caplan)
Bryan Caplan (homepage)
"The Common-Case Sense for Pacifism" (Bryan Caplan)
"Immigration Restrictions: A Solution in Search of a Problem" (Bryan Caplan video lecture)

Topics discussed:

0:20 - Intro to Bryan Caplan
1:44 - Signaling model of education: redistributing status
10:27 - What does signaling signal? Importance of conformity
16:34 - Learning how to learn?
20:04 - Education as "nourishing mother"?
27:20 - Hypocrisy and the provision of academia

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Timothy Williamson: Vagueness | WSB #33

March 27, 2018

The problem of vagueness stems from the sorites paradox. A heap of sand cannot be turned into a non-heap by removing a single grain of sand. A short person cannot become tall by growing one millimeter. Someone who is sober cannot become drunk by ingesting one tenth of a milliliter of alcohol. These conditionals hold regardless of what we take as our starting conditions. But if this is true, we can iterate the conditionals many times over, until we can prove that one grain of sand makes a heap, an 8-ft. tall man isn't tall, and someone who's just ingested a liter of alcohol is sober.

This ancient paradox has become one of the toughest puzzles in contemporary metaphysics and philosophical logic. During our conversation, Professor Timothy Williamson explains and rejects a few approaches, including supervaluationism, fuzzy logic, nihilism, and contextualism. His preferred solution, known as epistemicism, is much simpler: all vague predicates have a precise cutoff point - we just can't know where it is. Williamson supports this counterintuitive view with compelling accounts of meaning and knowledge. Meaning, he explains, is determined in part by aggregate use; since we cannot know all of the factors of aggregate use, we cannot know the exact meanings of vague terms. From this, we can infer that there are many cases in which we know something but do not know that we know it.

Next week: Bryan Caplan: The Case against Education

Visit http://williamnava.com or more info!

Interested in vagueness? Check out my interview with Graham Priest on the sorites paradox.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:
Vagueness (Timothy Williamson)
Tetralogue: I'm Right, You're Wrong (Timothy Williamson)
"I Do Not Exist" (Peter Unger)
"Vagueness Without Paradox" (Diana Raffman)

Topics discussed:

0:20 - Intro to Timothy Williamson
1:01 - Teaser for "Tetralogue: I'm Right, You're Wrong"
2:33 - The sorites paradox and vagueness
9:14 - Is it really a problem?
13:32 - Intro to epistemicism
17:32 - Supervaluationism
20:46 - Objections to supervaluationism
28:58 - Limits of iteration?
32:49 - Degrees of truth and fuzzy logic
40:44 - Peter Unger's nihilism: there are no heaps, or people, or any everyday things or concepts
44:43 - Vague claims aren't propositions?
47:23 - Contextualism
51:50 - Epistemicism: inexact knowledge and margins of error
58:51 - Meaning and use
1:03:01 - Knowledge sorites: not knowing what we know
1:06:47 - Indiscriminate appearances sorites
1:15:58 - A stipulated vague language?
1:20:31 - The meaning formation process
1:26:38 - Changes in the world and changes in language

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Michael Huemer: Ethical Intuitionism | WSB #32

March 20, 2018

Are there moral facts? If so, are they objective? Where do they come from? Do we have reason to think - or doubt - that our immediate ethical intuitions tell what us they are?

These are the questions I discuss this week with professor Michael Huemer. The metaethical landscape can be split up as follows: realists (those who think there are objective ethical facts) and anti-realists (those who don't). Realists, in turn, fall into two further camps: naturalists, who think objective ethical facts can be reduced to descriptive facts about the world; and ethical intuitionists, who think ethical facts (or "evaluative" facts) are of a different sort and cannot be reduced to descriptive facts. As Huemer puts it, ethical intuitionists argue that ethical facts have a different type of ontology. We go on to discuss the reasons we should trust our ethical intuitions to reveal moral facts, why ethical intuitions seem shakier than perceptual ones, and what the source of moral facts is. Finally, Huemer gives us a teaser for his upcoming book, Paradox Lost, in which he claims to solve ten famous paradoxes, including the Liar, Sorites, Newcomb's, and the Sleeping Beauty problem.

Next week: Timothy Williamson: Epistemicism

Visit http://williamnava.com for more info!

Interested in metaethics? I've discussed it before, with Tomasz Kaye.

Special thanks to Jackie Blum for the podcast art, and The Tin Box for the theme music.
Click here for the full list of episodes!

Sources:
Ethical Intuitionism (Michael Huemer)

Topics discussed:

0:57 - Metaethical landscapes: two ways to draw the map
5:24 - Reasons people dislike ethical intuitionism
9:52 - Why not doubt our ethical intuitions?
16:33 - What are moral facts?
19:25 - Is there a source of moral facts?
25:19 - Ethical versus perceptual appearances
27:30 - New book: Paradox Lost (Liar, Sorites, Newcomb's)

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