Based on the passage, it can be concluded that the author and Broyles-González hold essentially the same attitude toward

Nicole on March 4 at 07:05AM

Recap of 'ALL' 'NOT ALL' Quantifiers

I just wanted to understand a bit more how it turns into Some, then for Not All it turns into Some A, ~B. Could I just have a recap please?

3 Replies

on March 4 at 09:26PM

Hello @nicolebet,

Let's start with "all." The example Mehran uses is "All carrots are vegetables."
C - - - - - -> V

We have information about carrots. We know for certain that every single carrot is a vegetable. But we do not have as much information about vegetables. The statement above leaves room for a number of possibilities:

1. All vegetables are carrots.
2. Most vegetables are carrots.
3. Some vegetables are carrots.

But only one of these is a valid conclusion based on the information we have. I like to use the term "overlap." We know that the two categories overlap because all carrots are vegetables. The overlap group is 100% of the carrot population, but we don't know how it relates to the vegetable population. It could be 10%, 60%, or 100%, but we know that it is not 0% because there is some overlap. This is why "some" is the only valid conclusion.
C - - - - - - -> V
V - - some - - C

I'll make a new example for "not all."
"Not all mammals are primates."
There is some similar reasoning to the other example. "Not all" includes multiple possibilities:

1. Most mammals are primates.
2. Some mammals are primates.
3. No mammals are primates.

We don't know which, but they all have something in common: Some mammals are not primates. This is the only thing that we can say for certain.

Nicole on March 6 at 08:50PM

Thank you so much... using 'overlap' really helped it click.

Ravi on March 20 at 06:55PM

@nicolebet, great! Let us know if you have any other questions!