Final answer:
Kantianism and rule utilitarianism may disagree on the morality of lying to prevent harm; Kantianism deems it always wrong due to the impossibility of universalizing dishonesty, while rule utilitarianism may find it acceptable if it leads to greater overall happiness.
Step-by-step explanation:
An example where Kantianism and rule utilitarianism disagree about the morality of an action could involve a situation where telling a lie is necessary to prevent harm. Under Kantianism, lying is always considered unethical because it violates a perfect duty to tell the truth, which Kant believes cannot be universalized without contradiction. Immanuel Kant's categorical imperative stresses that actions must be acceptable as a universal law, thereby deeming lying always wrong regardless of outcomes.
On the other hand, rule utilitarianism would evaluate the ethical nature of lying based on the rule's ability to promote overall happiness. If a rule like 'do not lie' generally leads to the greatest happiness, but in a particular case, lying would avoid significant harm and increase happiness, rule utilitarianism may consider lying ethical in that specific scenario. This approach assesses morality based on the consequences of following certain rules, therefore differing from the unyielding nature of deontological ethics.
Theoretical conflicts arise because the frameworks prioritize different aspects of ethical behavior. While Kantianism prioritizes adherence to moral principles regardless of outcomes, rule utilitarianism allows for exceptions to rules if following them would not result in the greatest happiness.