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Most Basic Logical Reasoning Question

Mi Kal
LSAT Leader
 
Posts: 48
Joined: Sat Jun 10, 2017 8:07 pm
Points: 48

Hi.

I am just at the beginning of reading the Logical Reasoning Bible. I believe I am probably overthinking things, but I am having difficulty getting past this most basic of points. There is an example that states:

"All Professors are ethical. Mason is a professor. So Mason is ethical."

Then it explains how the first two sentences are Premises and the last sentence is the Conclusion. When I look at the Stimulus, the only thing, for me, that points to the last sentence being the Conclusion is "So." I feel like I could rearrange the sentences in any order and that any of the sentences could be the Conclusion as long as it has the "So" at the beginning.

"All Professors are ethical. Mason is a professor. So Mason is ethical."
"All Professors are ethical. Mason is ethical. So Mason is a professor."
"Mason is ethical. Mason is a professor. So all Professors are ethical."

Could that work? Or am I just completely missing the point.

Thanks.

Michael
Dave Killoran
PowerScore Staff
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Hi Michael,

Thanks for the question! No, you haven't missed the point at all! that conclusion indicator is huge in that example, and as you will see shortly, I'll begin talking about how words like so, thus, therefore, hence etc all work to indicate that a conclusion is forthcoming.

One consideration that will also come up later is the idea of valid argument forms (as in, is the argument sound and do the premises justify the conclusion), and in your three examples, that would look like:


    "All Professors are ethical. Mason is a professor. So Mason is ethical." — this is a valid form, meaning that if you take just the two premises and analyze them alone, the result is indeed the stated conclusion. This argument uses conditional reasoning, which appears all over the LSAT so you will see this argument form again many more times (and, we call it the Repeat Form for easy reference). Using basic symbols, the argument appears as follows:


      Premise: A :arrow: B
      Premise: AM
      Conclusion: BM

      In the form above, A = professors B = ethical, and the sub-M = Mason

    "All Professors are ethical. Mason is ethical. So Mason is a professor." — this is not valid, meaning that if you isolate just the two premises, they do not result in the stated conclusion. Instead, this argument commits. an error that will be examined in detail later, and is known as a Mistaken Reversal. you'll see this error in both LR and LG.

    "Mason is ethical. Mason is a professor. So all Professors are ethical." — this is not valid, meaning that if you isolate just the two premises, they do not result in the stated conclusion.

There is a lot more coming on arguments, premises, and conclusions, as well as validity, so you are just at the start. But you are right on the money to notice how certain words are indicators that certain things are occurring.

Please let me know if that helps. Thanks!
Dave Killoran
PowerScore Test Preparation
Follow me on Twitter at http://twitter.com/DaveKilloran
My LSAT Articles: http://blog.powerscore.com/lsat/author/dave-killoran
Mi Kal
LSAT Leader
 
Posts: 48
Joined: Sat Jun 10, 2017 8:07 pm
Points: 48

Thanks Dave.

That helps a lot and I think I had a break through last night as I continued reading.

Michael