Since there is no survival value in an animal's having an organ that is able to function when all its other organs ha...

Skylar on May 10, 2020

@haleymacha, happy to help!

We can break down the passage from #2 as follows (where "P" stands for "Premise" and "C" stands for "Conclusion"):

P: It is probably within the reach of human technology to make the climate of Mars inhabitable.
P: It might be several centuries before people could live there, even with breathing apparatuses, but some of the world's great temples and cathedrals took centuries to build.
C: Research efforts now are justified if there is even a chance of making another planet inhabitable.
P: Besides, the intellectual exercise of understanding how the Martian atmosphere might be changed could help in understanding atmospheric changes inadvertently triggered by human activity on Earth.

In an argument, premises will always be statements that support another statement in the passage. In contrast, the main conclusion of an argument will always be the one statement that is supported by all other statements in the passage but does not support anything else in turn. If you are stuck, you should take a step back and ask yourself what everything in the passage is supporting. This will be your conclusion.

You mention the statement that we identified above as the first premise. Let's discuss a few of the key differences between this and the statement that we identified as the conclusion. 

(1) The first sentence works to support the conclusion, and the conclusion does not support any other statement. The first sentence presents the idea that it's possible for humanity to make Mars inhabitable. In other words, it says there is a chance of making another planet inhabitable. This is the second half of the statement that we identified as the conclusion, which says that research efforts are justified if there is a chance of making another planet inhabitable. Since we now know that there is a chance, we can conclude that research efforts are justified. In this way, we see the conclusion building upon the support offered by the first premise to lead to a new and larger statement. Everything in the passage is supporting the idea that the research efforts are justified.

(2) It may also be helpful to note that the statement we identified as the conclusion seems to make more of a claim than the first sentence does. Whereas the first sentence appears to offer a more passive fact, the conclusion goes further by deciding what is "justified," thereby setting up the passage as an argument. 

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

logan.cay34 on October 24, 2022

What does the term "justified" mean in the third sentence?

Emil-Kunkin on December 18, 2022

In this context justified would mean that it is appropriate to so. That is, it would be correct to fund this research.