Psychologist: Psychotherapists who attempt to provide psychotherapy on radio or television talk shows are expected t...

Jay-Etter on January 16, 2022

Hi Carol,
Good question, the difference is very tricky to see here.
The conclusion of the argument is that psychotherapists should never provide psychotherapy on talk shows. Why? Because doing so nearly always means the psychotherapist is not providing high-quality psychological help.

The question here is asking which principle MUST be assumed, and is therefore a strengthen with necessary premise question. Remember that Necessary premises must be true if the argument is to work, and we can check our answer options with the negation test. If the negation of an answer option ruins the argument, then it is the correct answer. If the negation of an answer option does not destroy the argument, then this answer is incorrect. We have to be careful not to mix up necessary assumptions with sufficient assumptions. While sufficient assumptions 100% logically guarantee the conclusion, they don't necessarily HAVE to be true for the argument to work (they could provide even more info than what is required, for example).

The difference between C and E hinges on the distinction on a necessary and a sufficient assumption. C is a sufficient assumption because if it is true, then we know that the conclusion is right and psychotherapists shouldn't provide psychotherapy on talk shows. However, C is NOT a necessary assumption. Why? Because it's talking about psychotherapy in general, not about psychotherapists. The negation of C is that psychotherapy may potentially be provided when there is a chance it's poor quality. However, this doesn't ruin the argument because maybe psychotherapists are held to a higher standard, for example. Answer option C might tell us your friend could never attempt to offer you psychological help, which is something that we don't need for the argument.

E, on the other hand, specifies psychotherapists, which is what the argument names in the conclusion. The negation of E, that psychotherapists may potentially provide help even if it's unlikely to be high quality, would ruin the argument because then it takes away all evidence for our conclusion. There would be no reason the psychotherapists couldn't do therapy on talk shows.