I’m morally under obligation to do the best I can by her.

我在道义有责任尽量善待她。

"What you did wasn't actually against the law, but it was morally wrong."

"你所做事正触犯法律,但在道义是错误。"

I felt morally obliged to do the best I could for her.

道义我感觉必须尽我所能为她效劳。

Tom refused to join the army, believing that he had no moral right to kill.

汤认为自己在道义无权杀人而拒绝入伍。

He deceived us into believing that he could give us moral support.

他骗得我们相信他能给我们道义持。

Your action contrast with your principles.

你行为和道义对比时就显示出差别。