PT70 Section4 # 23 Diagram Question

keeper962

For #23:Parallel Flaw
like in #17 I had trouble diagramming a part of this stim.

The stimulus says that:
Almost every SP in the past had MTC
Using MTC to introduce VB
Therefore VB will be a SP

I diagrammed:
A-->B
B-->C
-----------
C-->A

But for "Using MTC to introduce VB" is suppose to be diagrammed as:
C-->B

Why? And why is my diagram wrong?

cjones76

They aren't saying every time we use MTC it will be to introduce VB. There could be other reasons they are using MTC. Instead they are saying to introduce VB they will be using MTC. So, if it is VB then they will be using MTC. Therefore if you were to diagram it VB would be the sufficient condition to MTC.

Additionally, the first statement "Almost every SP in the past had MTC" would be a most statement.

Honestly, I think this problem is easier/quicker if you don't focus on diagraming it and instead look at the language and structural relationship.