Introducing heterogeneous beliefs into a contracting framework allows for considering ethical behavior. Optimal contracts with heterogeneous beliefs need to balance the standard effects of risk aversion and incentives for effort with the desire for exploitation. We study the situation where the principal additionally takes an explicit ethical stance: The agent must not be worse off from accepting the contract than the agent’s outside option according to the principal’s beliefs. In this framework, heterogeneous beliefs still matter, and we fully characterize the optimal contract with an overconfident agent. The agent is strictly better off with an ethical principal. The ethical principal may be better off with an overconfident agent, leading to Pareto improvements in welfare.