The main point to an argument is what the author wants to convince us of. For that reason, main points are often the most opinionated statements an author will make. Words like “must,” “clearly,” and “should” show up a lot in a lot main points — they’re words authors use when they want to persuade us.
Main points are also supported by evidence. In fact, all of the evidence in an argument will support the main point. So another way to find the main point is to figure out which statement is supported by the rest of the argument. One way to do that: find the statement you think is the main point, and ask yourself, “Why is this true?” If all of the premises in the argument help explain why that statement is true, then you’ve found the main point.
Here, all most opinionated statement the author makes is “Thomas must have seen it (the fire), whatever he now says to the contrary.” Notice the “must” — that’s a strong opinion! So this is a likely candidate for the main point.
Now, we can ask, “Why is it true that Thomas must have seen the fire?” Well, the other statements in the argument show that the fire was going on at the time and location of Thomas’s daily commute, anyone who was near the fire would have noticed it. These facts support the claim that “Thomas must have seen” the fire, confirming that this claim is the main point.
(E) is a premise. It establishes that Thomas was in the vicinity of the fire. But that premise is used to support the ultimate contention that Thomas must have seen the fire.
