MGMAT Blog CR Question

[samwong]

Recently, an instructor posted some CR logic in the blog:

http://www.manhattangmat.com/blog/index ... ive-logic/

A lot of things that the instructor discussed in that blog were not discussed in the CR strategy guides that I had studied (MGMAT CR, MGMAT Foundation of Verbal, and PowerScore CR bible.) I want to get an opinion from other instructors. Are the the things discussed in that blog necessary or helpful to improve CR? or is it too cumbersome for someone who has never taken a logic class? I was a bit overwhelm by all the technical terms discussed in the blog. (ie: Modus Tollens)

Thank you.

[RonPurewal]

Those are all just funky names for things that, given the right context, you've known since you were seven or eight years old.

For instance... If it's raining, then the ground is wet. Okay. I can only speak for myself, but I don't need Latin terminology to figure out that, if the ground is dry, then it's not raining. Hmm.

If you're programming a computer"”which can't think like a human (even a small child)"”then these concepts are useful for programming crude "logic circuits".
If you're not, then you should find that they are nothing more than non-intuitive ways of expressing highly intuitive ideas.

At least they look cool written down, though!

In other words, I doubt that the author of the blog post"”or anyone else"”actually uses these names and notations, consciously, while looking at a CR problem. (There's no way I could even think about doing that, unless I had an hour for each problem.) Most likely, it's just an explanation, in retrospect, for something the author would personally consider with normal intuition.
That's my hypothesis. I could be wrong, but I'd bet a fair amount of money on it. (See the example with rain, above.)

I can't imagine than anyone, even a professional digital logician, could actually manipulate these rules in real time, especially insofar as they apply to a critical reasoning problem.

[RonPurewal]

I do the same thing when I answer SC posts on this forum. I don't have any general rules memorized; I've been a writer and editor of English for a couple of decades now, so my mind is basically a huge repository of examples. If someone asks a good question (most of the questions in the SC thread are good questions), I just conjure up a million zillion examples in my mind, and then, once I see the pattern, I'll write it down on the forum. In retrospect.

[RonPurewal]

In fact, if you look through our CR book and/or the CR bible, you should find that everything in those books, too, is something that a 7- or 8-year-old could do in the right context.

The challenge of CR doesn't have anything to do with logic; frankly, studying the logic is at best an unproductive use of your time (and at worst a dangerous distraction from actual thinking).
The challenge lies in being able to take these intuitive patterns of "logic""”which you already understand as a small-ish child, in a simple and concrete enough context"”and apply them to situations that are considerably more remote from real life.

In other words, the challenge is to personalize the CR passages"”to involve yourself in them, to whatever extent.