#18 - "Physicalists" expect that ultimately all mental

[KelseyWoods]

Hi Blade!

Answer choice (A) describes an Internal Contradiction flaw, which actually could be a correct answer! (Not for this stimulus, of course.)

An example of this type of flawed argument would be:

"Everyone should join our country club. After all, it's an exclusive group that links many of the influential members of the community."

In this example, the conclusion that everyone should join the country club contradicts the claim that it is an exclusive group...it won't be exclusive anymore if everyone joins!

An Internal Contradiction is not the same as a Mistaken Reversal. In a Mistaken Reversal, the conclusion doesn't actually contradict the premises, it's just not something that we can prove with the premises. In an Internal Contradiction, the premises and conclusion actually have to be in opposition to one another, in other words the premise and conclusion cannot both be true.

We actually posted about this flaw recently on Instagram. So here's my shameless plug for our Instagram account and our brand new #flawfriday posts (they're my favorites--you can practice spotting a new flaw every Friday while you scroll through Baby Yoda memes and Christmas tree pics!): https://www.instagram.com/p/B5vTBUxJO3o/

And here's a blog post where we go into more depth about this flaw:
https://blog.powerscore.com/lsat/bid-28 ... radiction/

Hope this helps!

Best,
Kelsey

[rlouis1993]

Two questions:

(1) I started reading this and set up a conditional logic for the first sentence, "ultimately, all mental functions will be explainable in neurobiological terms." Clearly, this is not needed to answer the question, but I am wondering if you could let me know if I set up the logical condition correctly anyway:

Mental Functions ---> Explained in New Biological Terms
/Explained in Biological Terms ---> /Mental Functions

(2) For the logical condition that you highlighted in helping you answer the question correctly, is the word "required" what "sparked" your brain to identify the necessary conditions? Reason I ask is because it is a "trigger" word in our necessary indicators, but it seemed so miniscule with respect to everything going on in the passage!

[rlouis1993]

Also, do the majority of the "find the flaw in the reasoning" questions typically involve answer choices related to Mistaken Reversal and Mistaken Negation?

[Jeff Wren]

Hi rlouis1993,

1. Your diagram looks fine in the sense that "mental functions" would be the sufficient and "explained in new biological terms" would be the necessary.

One word of caution, however, while these "shorthand" terms are fine for diagramming purposes, it's important to always return to the exact/actual wording of the text when double checking answers because sometimes slight differences/nuances in the wording can be critical in distinguishing right and wrong answers.

What I'm trying to get at is that, with that diagram, it might be easy to think that we've established that "if something is a mental function, then it can be explained in new biological terms," while missing the caveats in the stimulus of the word "ultimately" and that this is just the expectation of the physicalists rather than a certainty.

2. Yes, the word "required" is the key. It may seem miniscule, but it is not! Sometimes, the only clue that you will get is the word "if." Such a small word, but so powerful! One of the difficulties in handling conditional reasoning in logical reasoning is spotting it when it's mixed in with all of the other questions.

A useful first step is to study/memorize the list of common sufficient and necessary indicator words and train yourself to actively look for them at all times. When you come across one, mental alarm bells should be going off in your mind. "Warning! Alert! Possible condition reasoning ahead!" Of course, there are many ways to convey conditional statements in English, and those lists are not comprehensive, but they are a good place to start.

To answer your final question, no, the majority of flaw questions do not involve Mistaken Reversals or Mistaken Negations. Those flaws are just two of the many flaws that appear in logical reasoning. Historically, on any given logical reasoning section that contained 3-4 flaw questions, there was a good chance that 1 of those on average would be a conditional reasoning flaw. On recent LSATs, however, conditional flaws have been appearing less frequently.

More information on the other common flaws on the test can be found in lesson 7 of The PowerScore LSAT Course and chapter 15 of The Logical Reasoning Bible.