Hi there G A —
Thanks so much for the kind comments and it’s great to hear that you are finding the Trainer and this site helpful —
I just took a took at that page, and I realize it’s a bit cruel of me to give that example without a more elaborate explanation — I realize it’s me going from 0 – 60 a bit too fast, and it’s understandable why the example might exacerbate any concerns you might have —
First, and most importantly — in terms of how an answer could fill the gap but not be a requirement —
One general way to think of it is that there are many different ways to solve a problem, and so one way that happens to solve a problem in reasoning doesn’t necessarily have to, absolutely, be a required way to solve a problem —
To elaborate with a more black and white example — if we use the argument:
“I have a total of $20. So, I have enough money to buy the ticket.”
An answer like, “The ticket costs less than $10” would certainly fill the gap, but it’s not something that has to be true in order for the argument to work, and so it’s not required.
An answer like, “The ticket doesn’t cost more than $50,” doesn’t fix our gap, but it is something that needs to be true for the argument to work.
Again, that’s the big, big takeaway, so I’m sorry if the coffee example confused you, and, if it continues to, don’t worry about it —
But in terms of an explanation for that —
In order for her argument to work, does it absolutely have to be true that coffee is the only substance she consumes that contains caffeine? —
Well, what if we were told that the water she consumes happens to have trace amounts of caffeine in it, or we find out that every once in a while she has a piece of chocolate, which happens to have some caffeine in it — would that destroy her reasoning? No —
To me, it has to do with the concept of “too much” —
To illustrate with a different situation — imagine the argument,
“My wife says I eat more than I should, but this is not true. Every night, I eat the recommended amount for someone my size for my dinner.”
In order for this argument to work, does it have to be true that he never eats any meal other than dinner? No — he hasn’t talked about his other meals, but that doesn’t mean that eating other meals would destroy the reasoning, and again, to me it has to do with the fact that we need to know something about eating too much.
That’s a really subtle issue, and again, don’t think of it as something central to understanding required vs important — but, I do hope that helps clear up your concerns, and if you have any follow-up, or need anything else at all, please let me know —