In this video, Matthew C. Harris explains the fallacy of affirming the consequent, the formal fallacy that arises from inferring the converse of an argument. He also explains why you sometimes cannot conclude that you should bathe in a tub of peanut butter.
We humans are a chatty bunch--we talk A LOT. But each claim we make can be sorted neatly sorted into one of two categories: it either describes something or it evaluates something (philosophers call these descriptive and normative claims respectively). In this video Kelley illustrates the descriptive/normative distinction, and it's importance, with the use of ample examples.
The concept of justification is fundamental to good, careful thinking. But what does it mean for a belief or action to be justified? In this video, Kelley sheds some light on how to assess whether a belief and action is justified. She also clarifies the notion of justification by distinguishing it from explanation and explaining its relationship to the practice of giving reasons.
This video will rock your world! You should watch it. This pithy little argument contains an implicit premise: "If a video will rock your world, you should watch it". In this video, Kelley will go over how to identify implicit premises in all sorts of arguments and discuss when it is and is not acceptable to leave a premise implicit.
What sort of things do we value and why? In this video Kelley distinguishes two different kinds of value: (1) Intrinsic value--the value that something has in itself--and (2) instrumental value--the value that something has because it helps us to get or achieve some other thing. This philosophically and practically useful distinction is illuminated through the use of plenty of examples and ordinary language glosses.
Jeff discusses the nature of moral status. What does it take for someone to be a subject of moral concern? Do they have to be human? Rational? Sentient? Alive? And how does our answer to this question affect how we should act in everyday life?
In this video, Josh Knobe describes a new philosophical tool called experimental philosophy. To explain the project, he introduces some new research from Felipe De Brigard, and he shows how it applies to a traditional problem in philosophy. He ends with a question for the viewers: does philosophy's new tool help us make progress on philosophical questions?
In this video, Paul Henne describes the fallacy of division, the informal fallacy that arises when we assume that the parts of some whole must have the same properties as the whole they make up. He also discusses why water molecules aren't wet.
In this video, Paul Henne describes the fallacy of composition, an informal fallacy that arises when we assume that some whole has the same properties as its parts. He also discusses why there aren't colorless cats.
In this video Kelley discusses one of the most basic tools in the philosophers's tool kit: the distinction between necessary and sufficient conditions. Through the use of ordinary language glosses and plenty of examples this mighty distinction is brought down to earth and presented in a ready-to-use fashion.
Jenn introduces us to a puzzle that has bedeviled philosophy since the ancient Greeks: the Ship of Theseus. She tells the Ship of Theseus story, and draws out the more general question behind it: what does it take for an object to persist over time? She then breaks this ancient problem down with modern clarity and rigor.
Part 2 of a pair. Stephen considers the relationship between morality and God. Specifically, he asks: is morality the same thing as the commands of God? Is there no morality if there is no God? Stephen thinks the answer to both these questions is 'no'. He argues that, if you believe God exists and that we should follow his commands *for certain reasons*, then you should *not* think that morality just is whatever God commands.
Part 1 of a pair. Agustin teaches us about some weird properties of infinity, using an example due to mathematician David Hilbert called 'Hilbert's Hotel'. He shows us a result proved by another mathematician, Georg Cantor: that many infinite collections of things are the same size. Things that are the same size include: the natural numbers, the natural number plus one, the natural numbers plus the natural numbers, and as many copies of the natural numbers as there are natural numbers! Amazing!
Richard discusses the classic philosophical problem of free will --- that is, the question of whether we decide things for ourselves, or are forced to go one way or another. He distinguishes between two different worries. One worry is that the laws of physics, plus facts about the past over which we have no control, determine what we will do, and that means we’re not free. Another worry is that because the laws and the past determine what we’ll do, someone smart enough could know what we would do ahead of time, so we can’t be free. He says the second worry is much worse than the first, but argues that the second doesn’t follow from the first.
Tom asks whether it is moral to believe something even when you have no evidence that it is true. He discusses a classic debate on that subject, between philosophers William James and William Clifford.
Part 2 of a pair. Tim moves on to the version of the Cosmological Argument for the existence of God called 'the Modal Argument.' The idea is that all the contingent facts about the world need to be explained by some necessary fact, and that necessary fact is that God exists.
Part 1 of a pair. Tim lays out a classic argument for the existence of God, called 'The Cosmological Argument' -- roughly, the idea that something has to explain why the world is the way it is, and that something is God. He distinguishes two versions: the Beginnings Argument, and the Modal Argument. He covers the Beginnings Argument.
William introduces us to different aspects of meaning, as studied by linguistics and philosophers. He tells us about the difference between the literal meaning of a sentence someone says, and what they intend to convey by using that sentence at that particular time.