- Tue Aug 13, 2019 4:32 pm
lane and adkirk,
This is a difficult question. We have two arguments, Wirth's and Chang's and it is important to keep the two distinct.
First, we need to understand each argument and then the question stem.
Wirth's argument boils down to p1: none of the many attempts to find a m-d gene has succeeded p2: nearly all researchers agree that there is no (single) m-d gene. C: No one is genetically predisposed to m-d
Chang's argument is there are several genes involved that interact and from that is the disposition to m-d. This means that there is, in fact, a genetic predisposition.
First, we note that Chang is explicitly accepting the two premises. He is rejecting the conclusion, but he is not explicit as to why. The best place to prephrase this flaw in Wirth's reasoning would be while reading the stimulus. In this case, it is begging to be found because of Chang's disagreement. So what is the flaw?
Well, just because m-d doesn't result from a single gene doesn't mean there can be NO genetic predisposition because there is a missing possibility, namely multiple genes causing a predisposition to manic depression.
So, now we understand the premise, we turn to the question stem. It is a second order question because it is not simply asking for one argument or the other but for Chang's criticism of Wirth's argument. We can use our prephrase: Chang thinks Wirth's argument is flawed because he ignores the possibility that a genetic predisposition can be caused by multiple genes.
That prephrase gets us to A. The "it" in the answer choice is confusing, but "it" refers to Wirth's argument. So, if we were to flesh out the answer (always a good thing to do for these abstract answers), we would write "Wirth's argument presupposes only one possibility (genetic dispositions are caused by single genes only) where more than one (genetic predispositions can be caused by single genes OR by multiple genes) exists."
So, adkirk, you are off because you are primarily analyzing potential flaws in Chang's argument (you say "how do we know Chang presupposes..." and "leading Chang to contradict...") We are not supposed to look for flaws in Chang's argument. On the contrary, we are to "think like Chang" and find flaws in Wirth's argument, i.e. "accurately express Chang's criticism". The first "It" in each answer choice should be "Wirth's argument" NOT "Chang's argument".