LSAT 138 | Section 3 | Logical Reasoning: Q20

LR Question 20 Explanation

QUESTION TEXT: Scientist: Given the human tendency to explore and…

QUESTION TYPE: Method of Reasoning

CONCLUSION: There are low odds that humans will colonize the universe.

REASONING: If we colonized, most humans would be alive during the era of space colonization. We are not alive during this era, so it’s unlikely it will ever happen.

ANALYSIS: The author is attempting to make a probabilistic argument. The author’s error is that he hasn’t taken a random sample out of all humans that ever existed. He’s only looking at our time.

Imagine if you could survey all of human history and ask 1000 people at random from different times: ‘does space colonization exist?’. If they all say ‘no’, then it’s likely it never existed.

This method doesn’t work if you only survey your own time. It could just be that colonization hasn’t happened yet.

In terms of formal procedure, the argument says space colonization will never occur because a something that would probably accompany space colonization (a population explosion) hasn’t occurred yet.

___________

1. Tempting, but the argument isn’t as simple as this. An example of this reasoning would be ‘He hasn’t arrived, therefore he never will’.
2. This is a different error. To choose this answer you would have to be able to specify which premise was contradicted and why.
3. This statement is way too broad. The argument is talking about space colonization, not all situations.
4. CORRECT. The event that is likely is ‘we are alive during the era of colonization’. The given hypothesis is ‘space colonization’. So since we don’t live in an era of space colonization, it is unlikely space colonization will happen.
5. This isn’t necessarily an error. For example, I’m confident in predicting that humans will still be breathing oxygen in 500 years.