# Search for tag: "syllogism"

#### CL - Lecture 4a - Aristotle's Rules

Our first video is a recap of last week's materials.

From  Haoran Peng 0 likes 546 plays 0

#### CL - Lecture 3j - Aristotle's Syllogisms

We describe the traditional presentation of the syllogisms, and introduce Aristotle's existential assumption, on the basis of which he derives nine more syllogisms. These are not sound in our…

From  Haoran Peng 0 likes 443 plays 0

#### CL - Lecture 3g - Making more rules with contrapositions

Using meta-/object-level contrapositions, we can derive all 15 sound syllogisms from Barbara.

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#### CL - Lecture 3f - Presenting your justifications and counterexamples

In this video, we label each region in the Venn diagram with a number from 0 to 7. We can then present our justifications and counter-examples by referring to those 8 regions.

From  Haoran Peng 0 likes 480 plays 0

#### CL - Lecture 3e - Constructing a Counterexample

In the last video, we showed a rule is sound using Venn diagrams. In this video, we will again use Venn diagrams to construct counter-examples for unsound rules.

From  Haoran Peng 0 likes 494 plays 0

#### CL - Lecture 3d - Using Venn Diagrams to show a Syllogism is Sound

Given a syllogistic rule, how do we show that it is sound? Here we show that using Venn diagrams.

From  Haoran Peng 0 likes 454 plays 0

#### CL - Lecture 3c - Aristotle's Square of Opposition

This is how Aristotle organised his propositions.

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#### CL - Lecture 3b - Particular Propositions

You have already met Aristotle's universal propositions, universal assertion, "every a is b", and universal denial, "no a is b". The negations of these are his particular…

From  Haoran Peng 0 likes 483 plays 0

#### CL - Lecture 3a - Contraposition of Propositions

Last week we used object-level contraposition to derive four new syllogisms, starting from Barbara. This week we will use meta-level contraposition to derive two more new syllogisms from each of the…

From  Haoran Peng 0 likes 725 plays 0

#### CL - 2019 Lecture 2

This is an old recording of Lecture 2, from 2019.

From  Claudia-Elena Chirita 0 likes 193 plays 0

#### CL - Lecture 2.e - Aristotelian Syllogisms. Another Example

In this video, we get syllogisms for free! We see how some simple reasoning allows us to derive three more syllogisms.

From  Claudia-Elena Chirita 0 likes 474 plays 0

#### CL - Lecture 2.d - Negation and Contraposition of Predicates

In this video on syllogisms, we introduce the logic of negation.

From  Claudia-Elena Chirita 0 likes 479 plays 0

#### CL - Lecture 2.c - Aristotle’s Universal Propositions

In this video on syllogisms, we present a new form of proposition -- universal denial. Introducing negation gives a new syllogism as an instance of barbara.

From  Claudia-Elena Chirita 0 likes 462 plays 0

#### CL - Lecture 2.b - Aristotelian Syllogisms. First Example

This is the third video on Syllogisms. We use Venn diagrams to show that barbara is sound.

From  Claudia-Elena Chirita 0 likes 492 plays 0

#### CL - Lecture 2.aa - Aristotelian Syllogisms. Venn diagrams

This is the second video on Syllogisms. We return to discuss the relationship between Euler and Venn diagrams, and introduce some notation.Having watched this video, you should be able to count how…

From  Claudia-Elena Chirita 0 likes 505 plays 0

#### CL - Lecture 2.a - Aristotelian Syllogisms. Euler diagrams

This is the first video on Syllogisms. We start by introducing barbara, the simplest classical syllogism, and the proposition, "all a are b", known as universal affirmation. We briefly …

From  Claudia-Elena Chirita 0 likes 585 plays 0