Final answer:
True The claim that moral premises cannot be evaluated is false; they can be assessed for truthfulness, relevance, and adequacy. Concepts like 'no false lemmas' and the distinction between 'ought' and 'is' demonstrate the importance of evaluating premises in moral reasoning.
Step-by-step explanation:
The statement that moral premises cannot be evaluated but must be either accepted or rejected is false. Premises in moral arguments, like any other premises, can indeed be evaluated based on their truthfulness, relevance, and ability to adequately support a conclusion.
Gilbert Harman's concept of no false lemmas emphasizes that true knowledge should not stem from falsehoods. In philosophy, evaluating premises is a critical skill, especially when trying to understand if an argument is valid or sound. For instance, deductive reasoning is structured so that if the premises are true, the conclusion must also be true.
However, if the premises are found to be false or questionable, the argument can become invalid or the conclusion might not necessarily follow.
Similarly, the problem of deriving ought from is, as discussed by Hume, reinforces the idea that moral assertions have to be scrutinized and understood within the context of human sentiments and not just facts.