- Teach writing → Serve well
+
Some philosophy courses → teach writing
- Combine these statements; think about the argument structure like this:
Some philosophy courses → teach writing → Serve well.
THEREFORE...
All philosophy courses → Serve well
The argument structure is simple. It gives a conditional, (T → SW), then adds a link to that conditional, (some P → T → SW), and then concludes, (all P → SW). This makes logical sense...
...EXCEPT FOR THE PART GOING FROM "some" TO "all." This is the flaw!
By saying that "some" classes have a certain property, we cannot say that "any" class will have that property or "all" classes have that property! We want to find an answer choice that shows this.
(A) We don't care about how the course does this. This is a non-issue. Eliminate.
(B) Careful! The flaw in this argument is that it actually draws a stronger conclusion than is warranted. The premises say "some," the conclusion says "all;" that is much stronger!
(C) This is the opposite of what we want! We want to actually say that the argument "presumes, without providing justification, that what is true of each constituent part must also be true of a whole." In other words, this has it all flip-flopped!
(D) Like (A), this is a non-issue and doesn't address the flaw. We don't need to know more about students in certain majors or what classes they take
(E) This is perfect! It absolutely draws a conclusion about all cases ("any philosophy course...") from some cases of the kind ("some philosophy courses...")