If moral theories measure outcomes or consequences, then they do not concern duty. If trolley cases are compelling, then moral theories measure consequences. Moral theories concern duty. So, trolley cases are not compelling.
-Working backward from the conclusion of this argument, which of the following is the most likely justification of the last step of the derivation?
A) Com
B) DS
C) MT
D) MP
E) CD

Question

Quizplus · Accepted Answer

The last step of the argument, "So, trolley cases are not compelling," can be justified by the use of modus tollens (MT). MT is a valid form of deductive reasoning that infers the negation of the consequent from the negation of the antecedent. In this case, the antecedent is "If trolley cases are compelling, then moral theories measure consequences," and its negation is "Trolley cases are not compelling." The consequent is "moral theories measure outcomes or consequences," and its negation is "moral theories do not measure outcomes or consequences." Therefore, by the MT rule, we can conclude that "moral theories do not concern duty."

If Moral Theories Measure Outcomes or Consequences, Then They Do