If temperatures had dropped below freezing when I was gone last week, the impatiens in my garden would have died. If ...

Ryan on October 18 at 01:38PM

Why is A correct? Why is C incorrect?

Thanks

1 Reply

Irina on October 18 at 05:20PM

@Ryan-Mahabir,

The pattern of reasoning in the stimulus is as follows:

IF temperatures dropped (A), THEN impatiens died (B), THEN they would not bloom (C).
Impatients bloom (~C)
Therfore, temperatrures did not drop (~A):

A -> B -> C
~C
Therefore, ~A.

Let's compare it to (A) and (C).

(A) IF species are adaptable (A), THEN they will thrive (B).
IF species thrive (B), then it will have an adverse effect (C).
No adverse effect (~C).
Therefore, not adaptable (~A).

A->B->C
~C
Therefore, ~A

This pattern of reasoning is identical to the stimulus.

(C) IF a species is introduced to a new environment (A), THEN it adversely affects other species (B), but only if it adapts well to it (C).
IF a species does not adapt (~C), THEN it will not adversely affect any species (~B).

A & C -> B
~B -> ~A v ~C
~C
Therefore, ~B

This is a flawed argument and is different from the stimulus.

Let me know if you have any further questions.