Since anyone who makes an agreement has an obligation to fulfill the terms of that agreement, it follows that anyone ...

Naz on September 3, 2015

Alright, let's diagram:

"Since anyone who makes an agreement has an obligation to fulfill the terms of that agreement,"

P1: MA ==> HO
not HO ==> not MA

"it follows that anyone who is obligated to perform an action has agreed to perform that action."

Subsidiary Conclusion: HO ==> MA
not MA ==> not HO

Conclusion: "saying that one has a legal obligation to perform a given action is the same as saying that one is required to fulfill one's agreement to perform that action."

There are two big issues in this argument. The first is that we are taking a sufficient condition, "agreeing to perform an action," i.e. "MA," and mistaking it for a necessary condition in our subsidiary conclusion. Remember, a valid contrapositive will negate AND reverse the conditions of the principle rule. Second, we make a conclusion about LEGAL obligations when we were merely talking about having obligations in general. Thus, the argument is also accepting without any evidence that any obligation to perform an action constitutes a legal obligation.

Therefore, answer choice (D) is the correct answer because it accurately illustrates the above two flaws: "The argument treats a condition that is sufficient to make something an obligation as also a requirement fro something to be an obligation, and it takes for granted that any obligation to perform an action is a legal obligation."

Hope that clears things up! Please let us know if you have any other questions.