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Back to Think Again II: How to Reason Deductively

Think Again II: How to Reason Deductively, Duke University

4.5
148 ratings
22 reviews

About this Course

How to Reason Deductively Think Again: How to Reason and Argue Reasoning is important. This series of four short courses will teach you how to do it well. You will learn simple but vital rules to follow in thinking about any topic at all and common and tempting mistakes to avoid in reasoning. We will discuss how to identify, analyze, and evaluate arguments by other people (including politicians, used car salesmen, and teachers) and how to construct arguments of your own in order to help you decide what to believe or what to do. These skills will be useful in dealing with whatever matters most to you. Courses at a Glance: All four courses in this series are offered through sessions which run every four weeks. We suggest sticking to the weekly schedule to the best of your ability. If for whatever reason you fall behind, feel free to re-enroll in the next session.We also suggest that you start each course close to the beginning of a month in order to increase the number of peers in the discussion forums who are working on the same material as you are. While each course can be taken independently, we suggest you take the four courses in order. Course 1 - Think Again I: How to Understand Arguments Course 2 - Think Again II: How to Reason Deductively Course 3 - Think Again III: How to Reason Inductively Course 4 - Think Again IV: How to Avoid Fallacies About This Course in the Series: Imagine that a friend denies that modus ponens is a valid form of argument. Can you prove that it is valid without using modus ponens itself and thereby assuming that it is valid? If so, how? If not, what does this show about the validity of modus ponens? How can phrases like "and", "or", "if", and "not" work as "truth-functional connectives"? In this course, you will learn how to evaluate deductive arguments for validity. In particular, you will learn new ways of representing the information that is contained in the premises of a deductive argument. Using these new representational devices (devices that we call "truth tables" and "Venn diagrams"), we will be able to apply rules to determine whether or not a particular deductive argument is valid. Suggested Readings: Students who want more detailed explanations or additional exercises or who want to explore these topics in more depth should consult Understanding Arguments: An Introduction to Informal Logic, Ninth Edition, Concise, Chapters 6 and 7 by Walter Sinnott-Armstrong and Robert Fogelin. Course Format: Each week will be divided into multiple video segments that can be viewed separately or in groups. There will be short ungraded quizzes after each segment (to check comprehension) and a longer graded quiz at the end of the course....

Top reviews

By HP

Dec 02, 2017

Really good course, the material and explanations are good, and even in some cases, resolving or understanding some ideas is challenging, you can get the idea with a little practice

By SM

Jun 22, 2017

This entire series was informative, engaging, and fun, and the thinking skills taught are so valuable.

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20 Reviews

By darius

Jun 19, 2018

Great one!

By Carlos Del Rosario

Apr 29, 2018

amazing!

By Renato Almeida Domingues

Apr 24, 2018

Pros: I found the content very interesting. And there's an analogy with digital design (Boolean Logic) where F=1 and T=0 and so &=AND gate; V=OR gate; biconditional=XOR gate. Pretty useful content. Shorter 4week course. Well explained.

Cons: The exam is very hard. I dont see whats the point of making many & and V and conditional and biconditional together like a huge formula, it takes too much time the calculation. On Venn Diagrams when starts to become shaded and with crosses at the same time (using only 2 categories) I guess is not explained very well on the lectures.

Comparison with MOdule I: I found this module less applicable on the daily-life, more theoretical (but easier).

It's worthy every time anyway.

By Puni Puniglietto

Mar 13, 2018

I loved to take this course.

The professor is clever, funny and clear.

However, maybe because of being English my second language, I found difficult to get some issues ( i.e. "speech act" ) or understand the nuances in some exercises regarding "speech act" and" suppressed premises" (particularly in the final quiz, the more difficult questions to me were about the "suppressed premises").

So I would have liked that these harder issues have had found a clearer explanation during the lectures. Also in the final quizzes, it would have been useful giving the reason for the wrong answer (besides explaining the right one).

In fact, the quizzes are useful both for testing our understanding the matter and for learning from our mistakes too. In fact, we learn in a different and deeper way from our mistakes. To explain the reason for the mistakes is a good way to teaching and learning.

Although these notes, the course give enough awareness about our logical and linguistic skill and I'm going to take another one: "Think Again II: How to Reason Deductively". See you soon!

By matthew symes

Mar 04, 2018

Excellent !

By Euclides José Lima Velloso

Feb 16, 2018

Amazing course, something utile for everyone.

By Edwin Casper van Eersel

Feb 11, 2018

The professor teaching the course did a good job explaining the concepts behind deductive reasoning. There are however some minor things that annoyed me:

(1) Some of the definitions could have been more formal. Sure, you can describe a category as a "collection of things", but a more rigid approach is useful for the more mathematically inclined.

(2) Wrong answers in the quizzes are not always explained. You just see "You should not have selected this answer." Okay, but WHY NOT? The learning experience would be better if an explanation would always be given.

(3) Some parts are incomplete. For example, the topic on immediate categorical inferences only discusses conversion. It would have been nice to discuss the obversion and contrapositive inference as well. Another example is the lack of the explicit treatment of the biconditional introduction and elimination argument, while the conjunction and disjunction introduction and elimination methods are fully covered.

(4) The time spent on the course is short in comparison to Think Again I. For example, week 3 contains less than an hour's effort. Week 2 is also rather short. Instead of cutting it short, useful concepts such as the square of opposition, which is pretty much the basis of the relations between categorical propositions, could have been discussed.

(5) At the end of one of the lectures, three links are given for further practice. One of the links didn't work.

(6) Some quizzes deal with material that is discussed in later sections.

(7) The exam was unbalanced. One lecture was about addressing the validity of an argument containing an unknown/ foreign word. The exam had many many questions about this (IMHO) less relevant subject.

All in all: the professor gets a 4.5, the content gets a 3, which makes a 4-.

By Ying-Yu Hsieh

Feb 10, 2018

Still not very clear about Venn Diagram.

By fozan talat

Dec 25, 2017

A must course for every thinking person .

By Michael Flynn

Dec 04, 2017

I am sharing my disappointment of the care taken by the lecturer in preparing for his lectures. He is obviously an expert in Logic, and must be very intelligent to hold his academic position - so I have given the course a pass mark.

For example his use of Venn Diagrams was sloppy. I had already worked out that I could use Venn Diagrams before he introduced the idea, and I had sketched unambiguous diagrams to help me visualize the use of quantifiers. The lecturer just used an X to mark the intersection between two sets. This is an imprecise way of showing the intersection, and he could have easily drew different Venn Diagrams that unambiguously showed the various quantifiers. Also why did the lecturer choose to sit in a crappy little room, and not even take time to remove distracting objects from the desk behind him etc. To me he sent a signal that he couldn't even take time to arrange for a appropriate background nor design clear visual aids for his students. There are other Logic courses, and I will try them and hope they are better prepared and more respectful of students.