#25 - Some anthropologists argue that the human species

[7ncomment@gmail.com]

I have a quick question related to this question.


The anthropologist's claim is that survival >>>> thriving in diverse environments.

I see how the author confuses the conditions, but let's say we run with the author's counter argument that

Thriving in Diverse Environments >>>> Not Surviving.

Now the law of logic says that contrapositives are "another side of the same coin" or functionally equivalent to their original statement.

So, now the counter argument also functionally says "surviving >>> not thriving in diverse environments" which is the logical opposite of the anthropologist's claim that survival >>>> thriving. Why isn't the author then correct, because the contrapositive of the author's argument effectively disproves the anthropologist's claim.

I am honestly confused by the fact that even though contrapositives are essentially putting forth the same argument, we are not always allowed to use them, like in this example where we only go based off what the author overtly says and not the hidden contrapositive.

[7ncomment@gmail.com]

"surviving >>> not thriving in diverse environments" which is the logical opposite of the anthropologist's claim that survival >>>> not thriving.

Meant to say survival >>>> thriving instead

[Luke Haqq]

Hi 7ncomment!

If I understand what you're asking (apologies if I've misunderstood), the two statements that you have diagrammed aren't quite the contrapositives of one another.

In general, if you have a statement in the form:

A B

The contrapositive of this statement would be:

B A

To your question of why the author isn't correct, the anthropologists point out that an ability to cope is necessary for survival. The author then points to an example of a species that could cope but still went extinct, and concludes from this that the anthropologists must be wrong. The author thus seems to be mistaken in believing that the anthropologists were claiming that an ability to cope was sufficient for survival, when their claim was actually that it was necessary for survival.

[7ncomment@gmail.com]

Hey Luke,

I guess my question was more about how since every argument can be expressed in two equivalent fashions (original way and the contrapositive way).

Why can't we just first identify the author's counter argument, which is:
thriving in thriving in diverse environments >>>> not surviving.

Then select the contrapositive of this counter argument, which creates:
surviving >>>> not thriving diverse environments.

Now we have a logical opposite of the anthropoligist's claim which was that
survival >>> thriving in diverse environments

Do you see what I mean about how at first glance, it seems like the author does not effectively disprove the argument made by the anthropoligst because he mistakes a necessary for a sufficient. But depending on what version of the argument (taking the contrapositive in this case) we choose, we actually do disprove the argument.

[Luke Haqq]

Hi 7ncomment!

If I understand what you've diagrammed, I don't think that's quite what the author's counterargument is. Your first diagram is:

thriving in diverse environments >>>> not surviving.

Phrasing this as a conditional statement is effectively saying, "If something thrives in a diverse array of environments, then it will not survive." But the author doesn't make that sort of conditional statement. Rather, the author presents a given species as an example of one that thrived in diverse environments but did not survive.