Statement: The only people for me are the mad ones.
As the explanation says, "the only" (as opposed to "only if" or just a stand alone "only") introduces a sufficient condition.
This gives us a diagram of:
PFM - -> mad ones
And it's contrapositive:
~mad - -> ~PFM
What you wrote is not actually the contrapositive, which may have been part of why you had trouble with this one. ~PFM - -> ~M is mistaken negation, because you negated the terms without reversing them. For the contrapositive, you have to both reverse and negate. The reversal and negation of PFM - -> M, thus, is ~M - -> ~PMF.
However, you didn't have to put this statement into it's contrapositive to diagram it. Though technically the contrapositive is still a correct way of diagramming the statement, for this one, you only need to find the sufficient condition and put it on the left side of the arrow, and the necessary condition and put it on the right. Our sufficient condition is PFM, which we know because "the only" precedes it, which makes the remaining condition necessary.
PFM - -> M
Hope this helps!
SheaFebruary 14, 2021
Very few explanations are sufficient and helpful. Many answers only serve to further confuse. Is this the instructional approach used by law professors?
