#16 - Anyone who believes in extraterrestrials believes in

[TSE]

I had trouble approaching this question. Should this question be diagrammed? I was torn between answer choice A and E. I could not distinguish between the two choices. I believe this Q has something to do with the lack of existence not proving anything. Both A and E mention that one of the mystical creatures is nonexistent leading to the belief of the other creature being mistaken.

[TSE]

Section 1 question 16 "Anyone who believes in extraterrestrials..."

[Nicholas Bruno]

You could diagram this question to visualize the concept in this question. I diagrammed the question like this

Extraterrestrials (term A) ----> UFOs (term B)
not UFOs (term B) ----- > not extraterrestrials (term B)

So you are looking for the answer choice that matches that pattern of reasoning. In general terms it would look like

Term A ---> Term B
Not Term B ----> not Term A

Question choices A and C are similar but there is one key difference (we will start by looking at C).

Choice C could be diagrammed like:

unicorns (term A) ----> centaurs (term B)
not unicorns (term A) ----> not centaurs (term B)

As you can see, rather than having the pattern in the conclusion as in the stimulus. Instead of reading Not Term B then not term A, the answer choice goes "Not term A then not term B."

Choice A has the correct order (and is thus the correct answer)

unicorns (term A) ----> centaurs (term B)
Not centaurs (term B) ----> not unicorns (term A)

This (Choice A) matches the stimulus and is the correct answer. Let me know if that helps!

[Nadia0702]

Hi PowerScore,

I am having a really hard time seeing the difference between correct answer choice (A) and incorrect answer choice (E). I feel like both are half right/half wrong.

In (A) how does "... so there are no unicorns either" parallel "a BELIEF in extraterrestrials is false as well"? To me, the last part of (E) is a better parallel ("so a belief in centaurs is mistaken as well").

Conversely, the first part of the second sentence in (A) "...it has been demonstrated that there are no centaurs" parallels "... the existence of UFOs has been conclusively refuted" much better than "..but it has been conclusively PROVEN that there is no such thing as a unicorn" in (E).

What is the difference between those two answers? What am I missing?

Thanks!
Nadia

[Nikki Siclunov]

Hi Nadia,

Thanks for your question - it's a tricky one Let's look at the argument more closely and figure out the flaw first:

Premise 1: Anyone who believes in extraterrestrials believes in UFOs:

• Believe in extraterrestrials Believe in UFOs

Premise 2: There are no UFOs

• UFOs

Conclusion: Belief in extraterrestrials is false as well (i.e. there are no extraterrestrials)

• Extraterrestrials

I think you were misled by the conclusion. When we say that someone's belief is mistaken, we aren't saying that they don't believe in whatever they claim to believe. Instead, we argue that the belief itself is false, i.e. that whatever they believe in does not exist. If I told you that your belief is God is false/mistaken/etc., what I mean to suggest is that God does not exist, not that you don't believe in God.

In the first premise, the author observes that if you believe in extraterrestrials, you also believe in UFOs. That premise establishes a conditional relationship between the existence of two beliefs, not between their validity. In other words, the first premise makes no pronouncement as to whether either belief is true or false. The second premise, however, does, holding that the existence of UFOs has been refuted, i.e. it negates the validity of the belief in the necessary condition, not the existence of that condition. Indeed, the second premise would only be significant if we knew that the existence of extraterrestrials depends on the existence of UFOs (extraterrestrials UFOs). No such claim was made in the first premise, which is why the second one does not trigger the contrapositive of the first.

Now, let's look at answer choice (A):

Premise 1: Anyone who believes in unicorns believes in centaurs

• Believe in unicorns Believe in centaurs

Premise 2: There are no centaurs

• centaurs

Conclusion: There are no unicorns

• unicorns

Just like in the stimulus, answer choice (A) establishes a conditional relationship between the existence of two beliefs, and then suggests that some people are mistaken in theirs. The second premise only concerns the validity of the belief in the necessary condition (whether centaurs exist or not), not its existence (whether anyone believes in centaurs or not). As in the stimulus, no conditionality was ever established between the validity of either belief, which is why the conclusion is similarly flawed. Your mistake was in failing to recognize that the conclusion of the stimulus is identical to the conclusion in answer choice (A), despite the different wording. To say that a belief in something is "false" or "mistaken" implies that whatever you believe in simply does not exist.

Of course, the conclusion in answer choice (E) also matches the conclusion we are looking to parallel. The problem with that answer chocie is that the second premise does not invalidate the belief in the necessary condition of the first premise. Instead, the second premise invalidates the belief in the sufficient condition of the first:

Answer choice (E):

Premise 1: Anyone who believes in unicorns believes in centaurs:

• Believe in unicorns Believe in centaurs

Premise 2: There are no unicorns

• unicorns

Conclusion: The belief in centaurs is mistaken (i.e. there are no centaurs)

• centaurs

This is a tough question, so let me know if this explanation makes sense!

[Nadia0702]

Thanks SO much Nikki! Great explanation - makes perfect sense. I now see both why the reasoning in the stimulus was flawed (which I don't think I saw originally) and why A) matches that flawed reasoning and E) doesn't.

You rock!

Nadia

[reop6780]

The correct answer is A while I chose answer D.

To me, answer D seemed most attractive in that the stimuli mentioned, " a belief in ET is false as well."

I assumed the flaw in the stimuli was to call a belief as false.

For example, the reason why I was not convinced of answer A was that it is not flawed or at least not flawed in the same way with stimuli.

U C

~C

hence, ~U


Answer A deals with phenomena not beliefs.

Answer D is in similar format but negates a belief like the stimuli.

Did I figure a wrong flaw from the stimuli?

[BethRibet]

Hi Reop,

Thanks for the question.

The phrasing in D indicates that "there is no good reason to believe". This is not as closely equivalent to the stimuli, which indicates that a belief has been "conclusively refuted". The original version is much more certain and definite, whereas the answer choice reads more like an opinion. Answer choice A says "it has been demonstrated", which is closer to "conclusively refuted". Both indicate actual proof.

Answer choice A actually uses the term "belief", so I'm not sure I'm following the argument that it deals with phenomena, rather than beliefs.

Hope this helps!

Beth

[est15]

Hi, I'm having trouble deciding between A and D because I see something wrong in both of these answers. In A, I feel like the answer is wrong because the last sentence should be "a belief in unicorns is false" (or something similar) to match with the above argument. Simply saying "so there are no unicorns either" doesn't seem to match with the conclusion of the argument. In D, I feel like the answer is wrong because "unjustified" is not the same as false. Could you help me understand these answer choices better? Thanks.

[BethRibet]

Hi Est,

Thanks for the question. You're right that both answer choices are flawed. A however, is more similar to the stimulus. The stimulus says that the existence of the creatures in one of the conditions has been "conclusively refuted" (i.e. proven wrong). The conclusion then states that a related belief must therefore be wrong.

A says that it "has been demonstrated there are no...", which is similar to "conclusively refuted".

D doesn't mention proof, just says there is "no good reason to believe". It's pretty close, but not as precisely similar as A.

Hope this helps!
Beth