Critical Reasoning

Zelda: Dr. Ladlow, a research psychologist, has convincingly demonstrated that his theory about the determinants of rat behaviour generates consistently accurate predictions about how rats will perform in a maze. On the basis of this evidence Dr. Ladlow has claimed that his theory is irrefutably correct.
Anson: Then Dr. Ladlow is not responsible psychologist. Dr. Ladlow"Ÿs evidence does not conclusively prove that his theory is correct. Responsible psychologists always accept the possibility that new evidence will show that their theories are incorrect.

Which one of the following can be properly inferred from Anson"Ÿs argument?

(A) Dr. Ladlow"Ÿs evidence that his theory generates consistently accurate predictions about how rates will perform in a maze is inaccurate
(B) Psychologists who can derive consistently accurate predictions about how rats will perform in a maze from their theories cannot responsibly conclude that those theories cannot be disproved
(C) No matter how responsible psychologists are, they can never develop correct theoretical explanations.
(D) Responsible psychologists do not make predictions about how rats will perform in a maze
(E) Psychologists who accept the possibility that new evidence will show that their theories are incorrect are responsible psychologists.

OA: B

Why not E?

neeti2711 wrote:Why not E?

What Anson is talking about is a condition NECESSARY in order for a psychologist to be responsible. Anson is saying that if a psychologist is responsible, the psychologist will accept the possibility that new evidence will show his or her theories to be incorrect.

Simply put Anson is saying that in order for X to be true Y must be true. This does not mean that if Y is true, X is true. It just means that if Y is not true, X is not true.

The difference between what Anson said and what E says, is that E implies that a psychologist's accepting the possibility that new evidence will show his or her theories to be incorrect is a condition SUFFICIENT for indicating that the psychologist must be responsible.

In other words, E is saying that if Y is true, X is true.

So, what Anson is saying is not the same as what E is saying.