"If the forest continues to disappear at its present pace, the koala will approach extinction," said the biologist. "...

Chris-Smutny June 9, 2020

Also, could you use the same variables for "forestation continues to disappear" and "deforestation". I confuse myself a lot when trying to tell if a phrase is similar enough to use the same variable when diagramming.

shunhe June 15, 2020

Hi @Chris-Smutny,

Thanks for the question! So let’s take a look at the sentence: all that is needed to save the koala is to stop deforestation. This isn’t your simple “all X are Y,” which would be diagrammed as “all” introducing the sufficient condition, X —> Y. This is “all that is needed,” which is different; we can reword this sentence “deforestation is all that is needed to save the koala,” or “deforestation is needed to save the koala,” and then we can see “deforestation is needed” clearly introduces a necessary condition (since it uses the word needed). So you shouldn’t just blindly assume that what follows “all” will introduce the sufficient condition; sometimes, “all” will take a different function in a sentence like it does here.

Yes, you can use the same variables for “forestation continues to disappear” and “deforestation.” Generally speaking, if they reference the same kind of concept (here: forests disappearing = deforestation), and are just synonyms, then you should feel free to use the same term for both of them.

Hope this helps! Feel free to ask any other questions that you might have.

iris.diaz823 June 21, 2020

I have this same question

erica-scott July 27, 2020

can you diagram it out with using "deforestation" instead of "forestation continues to disappear". thats what I did and I seemed to have gotten it wrong.

lsatdandy September 6, 2020

I'm sorry but this makes no sense to me at all. How could "Deforestation stopped => Koalas become extinct parallel the premise "Deforestation continues => Koalas approach extinction? Would it not be instead Deforestation stopped => Koalas survive (contrapositive)?