#22 - The druid stones discovered in Ireland

[LSAT2018]

I was rushing through the answers towards the end of the stimulus and immediately eliminated answers (B) (D) and (E) because I saw the words group and members and somehow thought of them as Composition and Division Errors (definitely my fault for not being cautious). That is why I chose answer (C) which describes Circular Reasoning, I thought that the author was just refashioning the statement that because stones discovered in Ireland are old, others are not old.
How do I distinguish the correct answer (E) from the incorrect answer (C) here?

[LSAT2018]

By the way, the reason I thought this was a form of Circular Reasoning is that I was reminded of Question 8 in Practice Test 24 (December 1997) Section 2 where different words express the same concept. How would this question different from Question 22 here?

[Dave Killoran]

Hi LSAT,

One point of interest here is that if you see three separate answers all referencing similar ideas (in this case, groups and members) it can be a signal that those ideas are central to what's occurring in the problem.

The question you are really asking is whether this is circular reasoning. It's not, because there's no statement or belief that directly implies the conclusion:

• Premise: The druid stones discovered in Ireland are very, very old.
  Premise: But this particular druid stone was discovered in Scotland;
  Conclusion: hence, it must be of more recent vintage

Simply saying that a stone is from Scotland and is therefore not old does contain a big assumption, and that assumption is outlined in (E).

But, compare that to the problem you cite from D97. In that problem, the circularity is quite clear: "Sociologist: The claim that there is a large number of violent crimes in our society is false...But since violent crimes are very rare occurrences..." That's a direct restatement of the idea; no such similar restatement exists here, just a reference to Ireland and Scotland, which are different.

Thanks!