If understanding a word always involves knowing its dictionary definition, then understanding a word requires underst...

#JW on September 21, 2019

Mehran's breakdown

I couldn't post this to the other thread for some reason, but the breakdown really is not clicking for me. If there's another way to explain this that would really help. Also, I have seen other people request this but I'd like to suggest that having a video explanation is extremely helpful even if it is not a logic games question. All of the lessons have video and voice interaction and I think that is a great aide when trying to see how an instructor does their explanation. Thanks and I hope theres another way to explain this. I was stuck between C, D, and E.

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Irina on October 15, 2019


The question asks us what inferences can we make from the given set of facts.
The first premise tells us that:

IF understanding the word ALWAYS requires knowing its dictionary definition, THEN understanding the word requires understanding the words that occur in this definition.

The premise is essentially telling us that IF understanding the word requires knowing its dictionary definition, so let's say to understand what "dog" means, one must know its dictionary definition, THEN one must also understand all the words in this definition "a domesticated carnivorous mammal that typically has a long snout, an acute sense of smell, nonretractable claws, and a barking, howling, or whining voice."

The second premise tells us:

But clearly there are people - for example babies - who do not know the dictionary definition of the words they utter.
Surely, there a person that says "dog" without knowing how it is defined in the dictionary.
This premise tells us that people, e.g. babies - say words without knowing the definition but we cannot tell whether these babies understand the words that they utter. Since there is no connection between the first and the second premise, we can infer that the correct inference is likely conditional on babies' understanding/ lack of understanding of the words they say. We can thus infer if these babies do indeed understand the words that they say, then the antecedent of the first premise is false - one can understand the word without ALWAYS knowing its dictionary definition as (E) correctly concludes.

Let's look at (C) and (D):

(C) If some words can be understood without knowing the dictionary definition, then babies understand some words.

This is an unwarranted inference. We know that babies utter some words without knowing their definition per premise (2) and even if we say that some words can be understood without knowing their definition, we still could not infer that babies do understand some words. It is true that they COULD understand words without knowing the definition in this hypothetical, but we cannot conclude that it must be true.

(D) If it is possible to understand a word without knowing its definition,then it is possible to understand the word without knowing any other word.

That's an extreme inference. We are only told that babies do not know dictionary definitions for some of the words they utter. Does it mean they understand these words? Does it mean they know no other words? No, none of these inferences are supported by our premises.

Let me know if this helps and if you have any other questions.

#JW on October 15, 2019

Thanks, and I do have a follow up question to D... I know this is going to sound absurd, but so are some of these questions... my only issue with it is not that is is or is not an extreme inference, but that I find it hard based on what we are defining the term some to be (at least one) to rule out D. My is reasoning is this and please tell me where I'm going astray.. if a person understands a word without knowing its definition, then how can we rule out the possibility that a person understands only that word?

Ravi on October 17, 2019


Happy to help. Let's look at (D).

(D) says, "If it is possible to understand a word without knowing its
dictionary definition, then it is possible to understand a word
without having to understand any other word."

The problem with (D) is that it goes way too far in its conclusion.
This is not something that follows logically from the content of the
stimulus because even if someone can understand a word without
understanding its dictionary definition, that doesn't mean that
someone can understand it without understanding any other word. It
could still be the case that in order to understand a word, you have
to understand some other words. Thus, we can get rid of (D).

Does that make sense? Let us know if you have any other questions!

Ravi on October 17, 2019

@Jwebb, the problem is that in your reasoning, you're failing to account for the fact that we are focused on what we can conclude based on what we've been given in the stimulus. Your reasoning relies on focusing on more than just what's in the stimulus, and this is why it's something that we cannot conclude based on what is in the stimulus.