If there are sentient beings on planets outside our solar system, we will not be able to determine this anytime in th...

Naz on August 20, 2013

The conclusion of the argument is the first sentence. "If there are sentient beings on planets outside our solar system, we will not be able to determine this anytime in the near future unless some of these beings are at least as intelligent as humans."

So: under the condition that there are sentient beings on planets outside of our solar system,

If we are able to determine this anytime in the near future, then some of these beings are at least as intelligent as humans.

Conclusion:

D ==> IH

not IH ==> not D

Our premise states: We will not be able to send spacecraft to planets outside our solar system anytime in the near future. And any sentient being on another plant capable of communicating with us anytime in the near future would have to be at least as intelligent as we are.

Premise: not S

Principle:

CC ==> IH

not IH ==> not CC

So, we are concluding that, unless some of these beings are intelligent, we will not be able to determine that they exist.

Premise: not S

Principle: CC ==> IH

Conclusion: D ==> IH

This is a strengthen with sufficient premise question. Remember that a sufficient premise is sufficient for a conclusion, if and only if the existence of the premise guarantees or brings about the existence of the conclusion. Therefore, we need to find the premise that 100% guarantees the conclusion. The way you want to attack these answer choices is two-pronged. Ask yourself, does it strengthen? If it doesn't, then cross it out and continue to the next answer choice. If it does strengthen, however, then ask yourself whether or not the premise guarantees the conclusion.

Premise: not S

Principle: CC ==> IH

Missing Premise: ?

Conclusion: D ==> IH

(A) is incorrect because it does not strengthen the conclusion. Whether or not there are sentient beings on planets in our solar system other than those on Earth is irrelevant to this argument because the author's conclusion only applies "if there are sentient beings on planets outside of our solar system." We are looking for an answer choice that both strengthens the conclusion of the stimulus and simultaneously guarantees the conclusion.

(B) is incorrect because it does not strengthen the argument. Any information about other beings and the conditions that would make them want to communicate with sentient beings outside their own solar systems is completely irrelevant to our argument. What makes a being "want" to communicate with sentient beings does not matter to our argument. This argument is about the ability to communicate, not the desire to communicate.

(C) is incorrect because it doesn't strengthen the conclusion. We already know that we will not be able to send spacecraft to planets outside our solar system anytime in the near future. Therefore, knowing a specific scenario in which we still cannot send spacecraft does nothing for us.

(D) is CORRECT because it addresses the assumption being made in the stimulus, that there are no other ways to determine these species' existence other than either sending a spacecraft out to them or communicating with them (which requires them to be intelligent), thereby strengthening it. If (D) is true, then to be able to detect the existence of sentient beings, we need to either be able to send a spacecraft over or communicate with the sentient beings to be able to detect their existence. And, since we know that we will not be able to send a spacecraft any time in the near future, to be able to detect them, we must communicate with them, which means they must be intelligent (which is exactly what the conclusion states). Therefore, (D) not only strengthens the argument but also 100% guarantees the conclusion.

Premise: not S

Principle: CC ==> IH

Answer Choice (D):

if D:

not CC ==> S

not S ==> CC

Conclusion: D ==> IH

We could also write answer choice (D) as D ==> S or CC. Because it is an either/or, we know not S ==> CC. So, without S, D ==> CC. Thus: D ==> CC ==> IH, which guarantees the conclusion by plugging the whole between not S and CC.

(E) is incorrect because it is does not guarantee the conclusion. We know from the stimulus, if they are able to communicate with us, then they are at least as intelligent as humans. Presenting us with the incorrect contrapositive of that statement, "If they are at least as intelligent as humans, then they are capable of communicating with us," does nothing to the argument. We need to close the gap between not being able to send a spacecraft to planets outside our solar system anytime in the near future with any sentient being on another planet capable of communicating with us anytime in the near future would have to be at least as intelligent as we are.

I hope that was helpful. Let me know if you have any other questions!

Deke on June 16, 2019

In these questions, as soon as you are done reading, and see the question stem, sometimes it helps to try to predict an answer before continuing to the answers, some of these answers are just so damn confusing to work out in your head, that reading them, and figuring them out in your head will push out the info from the stimulus.