To suggest that capital punishment is a different moral question for nomadic peoples living in tents, or other temporary shelters, than it is for societies with maximum-security prisons, involves what kind of reasoning

Relativism

Explanation:

Relativism is the theory that holds that morality is relative to the norms of one's culture. That is, whether an action is right or wrong depends on the moral norms of the society in which it is practiced. The same action may be morally right in one society but be morally wrong in another that is to suggest that capital punishment is a different moral question for nomadic peoples living in tents, or other temporary shelters, than it is for societies with maximum security prisons, involves relativism reasoning.