We present a theoretical framework of individual-decision making that incorporates both moral motivations and social influence into the utility function. The main idea of the paper is that individuals face a trade-off between their material individual interests and their desire to follow moral obligation. In our model, we assume that moral motivation is weak or conditional in the sense that it may be influenced by others' actions. Specifically, in our framework one's moral obligation is a combination of two main components: an autonomous component and a social component that captures the influence of others. Our theoretical framework is able to explain many stylized results commonly observed in the literature and suggests a different mechanism to explain economic behavior.