1.   A man has a moral duty to obey the law.

2.   In their view serving the state was the highest moral duty and no state had external obligations.

3.   It manipulates the environment, and it is able to enforce moral duties on those who are inclined to disregard them.

4.   No violation of moral duty is involved.

5.   One person might consider it his moral duty to fight and another to desist from fighting.

6.   She felt it was her moral duty to treat everyone equally.

7.   She has a strong sense of moral duty.

8.   Though not under a legal liability to maintain his illegitimate child, the father is under a moral duty to do so.

9.   ...the moral duty to uphold peace if at all possible.

10.   There is a sense of moral duty implicit in her writings.