The Limits of Reasoning: Logical Fallacies Eduardo GONZALEZ, Zara Akhtar, Tyler Handin, Ben Abueg

WOK Badge: Reason

Reason Journal

February 14- February 23, 2017

Questions to explore for project:

Evaluate the strengths and weaknesses of reason as a way of knowing. (November 2008/May 2009)

How reliable is inductive reasoning?


Through reading the chapter, I learned that that deductive and inductive reasoning are useful in everyday lives, but reason cannot act alone to provide truth. For this reason (no pun intended), it must build off of other WOKs such as sense perception. It’s very interesting to note that that reason is much more about the process that the actual content.


Focus question: Are humans instinctively rational?

My group and I decided to explore reason for our next badge because we find it very intriguing and something that’s very applicable to how we as humans approach situations in the real world. We want to focus on whether humans are instinctively rational; that is, do humans pursue systematic thinking to formulate deductive or inductive conclusions on a daily basis, and to what extent are those conclusions valid. We’re interested in exploring whether humans instinctively use valid or invalid reasoning in their daily lives.

My idea as we begin to approach the project is to create a “test” with various syllogisms and ask people to determine which conclusions are valid and which are invalid. For instance, in a situation in which “Santa is a goat, and all goats have beards,” the valid conclusion is that “Santa has a beard.” While this is true, there is a premise which is widely accepted as untrue. Nevertheless, the conclusion was attained through valid use of reason, because the conclusion was indeed the inescapable consequence of both assumptions.


We’re considering doing a play in which we show how rational thinking evolved from ancient times in which creatures went into small spaces to escape large predators.

Why is reason based on assumptions and not on truth and facts? and How reliable is reason as a way of knowing?

After discussing with Mr. Morrison, we decided to change our question to “How reliable is reason as a way of knowing?” and we’re moving toward showing that it’s only as reliable as the preceding assumptions.

Even if the conclusion is right, the premises may be faulty, thus the reasoning is not sound by itself. Without support from sense perception, memory, and other WOKs, reason does not provide reality but only a tool to navigate through life.


We’ve had plenty of time to talk within our group, and our now established idea is to present a lesson to the class regarding validity. Through this, we plan to prove that reason is a means of systematic thinking, but does not produce truth. This must inherently be regarded as the case because reasoning is based on assumptions, which are not truths. Validity is merely an insight into the process of thinking and whether a conclusion is an inescapable consequence, but does not correlate to reality. Rather, reason provides insight into aspects of truth by working strongly in conjunction with sense perception and past experiences. We’re going to show that reason alone as a WOK gives us a means to approach the world around us, not fundamental knowledge. We will culminate by concluding that assumptions must be used because reason does not give certainty, but only a means to come closer or further from it. We’ll conclude that reason is very applicable, but in most cases we use it together with other WOKs to extract its full value.


Is reasoning instinctual, or must it be learned?

In order to explore this question, I consulted a TED lesson by Kelleher and Varberg’s math textbook to learn about Zeno’s paradox. A paradox occurs when sound reasoning is used, but results in an irrational conclusion. Zeno’s paradox essentially states that in order to travel a certain distance, one half of the total distance must be travelled, and then one half of that distance must be travelled. This logic is valid, but the conclusion is that because a person must keep traveling half of the new distance, the endpoint will never be reached.

When I first read Varberg’s textbook, I was astounded and intrigued that reasoning could yield such absurd conclusions. However, in Kelleher’s TED talk video, I learned that even though the series (1/2 + 1/4 + 1/8 + 1/16 + 1/32 + 1/64…) has an infinite number of terms, the sum of this series is finite (and equals 1). Hence, in reality the distance will be reached in a finite time.

Exploring this paradox taught me that while basic reasoning might be instinctual, higher level reasoning must indeed be learned. For instance, Kelleher’s video displayed with a square (which has an area of 1) that that square can be cut up infinitely and still have the area of one. The corresponding analogy to Zeno’s paradox is that a distance can be divided into infinite fragments, but the total time it takes to cover that distance is a set number. Thus, without that learned mathematical knowledge, I would not have the component of reasoning necessary to understand why Zeno’s paradox actually has a small flaw in its logic and the conclusion actually works. Thus, reasoning to resolve paradoxes and complex problems must in fact be learned.


Today is our final workday to complete our presentation planning. We have established our question: How reliable is reason as a way of knowing? The main point is to show that reason alone does not provide truth and simply augments our other WOKs such as sense perception, intuition, memory, et cetera. We plan to show this by giving the class a lesson on validity. Through this, we will show how valid reasoning can be used to come up with absurd conclusions or how false assumptions may lead to a correct conclusion. This will enable the class to see that reason works well when used in sync with the other WOKs, but alone it is no more than a systematic process of thinking. Hence, we will summarize that in approaching real life situations, we incorporate a lot more ways of knowing than we’re aware. Ultimately, we will assert that reason is based on assumptions because is does not give certainty or truth.

We will achieve our goal by creating notecards and handing the class the premises and questions, while writing on the whiteboard.

2/21/17 -End of class

I learned that reason today is limited as a way of knowing to its premises, and truth is attained only through the consultation of other WOKs. I was very intrigued to learn that language is one of the main means through which reasoning is limited. Our presentation emphasizes that reason is a means of systematic thinking but when considered alone, has many limitations and does not provide much insight into truth and reality. We’re showing that when reason is relied upon too heavily, incorrect conclusions materialize. I learned the the logical fallacies are a perfect means to exploit reason’s imperfections.

Our group is moderately prepared for the badge project; we’ve pinpointed several RL examples and written premise cards to do an activity with the class. We have the necessary content to teach our lesson and will analyze the examples to make the point that reason alone does not lead to truth and has faults when other WOKs are not integrated.

We need to refine the lesson we’re teaching at the beginning of class regarding linguistic reasoning, and it will be based on introducing the logical fallacies and acquainting the audience with what each one does and why that occurs, highlighting the lack of incorporation of other WOKs. Other than that, we will do the activity with the class and discuss and analyze the results of said experiment. All will answer the question, “What are the limitations of reason as a way of knowing?”


Today we completed the badge project presentation, which went relatively well. We created a class activity for the audience members to come up with conclusions based on premises. Through the use of linguistic reasoning through logical fallacies, we showed that reason as a way of knowing is very limited and does not lead to truth unless it is melded with the other WOKs. We explored equivocation (ambiguous language), ad hominem, hasty generalization, and false dilemmas, just to name a few. These examples show that reason cannot be relied upon too heavily, and there are many ways to fall into the trap of using it wrongly, which is often seen in the real world. We concluded that reason is inherent to our daily lives as the systematic process guides us, but unlike other WOKs it alone cannot yield truth, as reason is based exclusively on premises (assumptions).

I think the activity we did took up more time than necessary, but we incorporated the audience and explained our rationale well. While it could have been more organized, I believe our performance allowed my classmates to directly comprehend what a logical fallacy was, and as a group we used this to show how reason is very limited as a way of knowing. We focused on the lens of language and the associated informal reasoning to prove that reason cannot yield truth alone It inevitably requires other WOKs in order to work well as a means of systematic thinking.

Knowledge questions explored:

1) Are humans instinctively rational?

2) Why is reason based on assumptions and not on truth and facts?

3) Is reasoning instinctual, or must it be learned?

4) What are the limitations of reason as a way of knowing?

Lesson on Reason by Mr. Morrison: Syllogisms and Validity

URL for PowerPoint presentation

The following are the cards used for our activity regarding logical fallacies:

Extension Proposal: The Monty Hall Problem

This problem stems from a game show. There are three doors for contestants to choose from: two of them have goats behind them, while one of the three contains the prize (a car). You are told to choose a door. Afterwards, the host opens one of the two remaining doors which has a goat. For instance, if you choose door 3 initially, either door 1 or door 2 will be opened to reveal a goat.

You are then given the option of switching doors. The questions is, should you switch or does it not matter?

Explanation website:

Explanation Video (Khan Academy):

Rationale: I came across this problem while reading a book for English, and it continues to fascinate me because it really messes with both reasoning and intuition . This explores the essential question, Is reason is instinctive or must it be learned? It becomes obvious that mathematical reasoning becomes multi-faceted and requires some learning. This problem is vey fun to explore and test the reliability of reason.

Made with Adobe Slate

Make your words and images move.

Get Slate

Report Abuse

If you feel that this video content violates the Adobe Terms of Use, you may report this content by filling out this quick form.

To report a Copyright Violation, please follow Section 17 in the Terms of Use.