The purpose of this study is to examine the ethical aspects and consequences of the feasible duty. The first hypothesis of the study is that the feasible duty also includes ethical recommendations and commands. The second hypothesis is the role of the feasible duty as a strategic principle to prevent harm in moral and educational systems. The third hypothesis is the assessing and psychological role of this principle in the efficiency and effectiveness of ethical and educational systems and the ethical evaluation of the professional systems and legal systems. The research is based on the position of Shiite scholars on the challenges of the unfeasible duty. There are two interpretations of the feasibility: feasibility in the sense of strength and feasibility in the sense of less than tolerability. The research hypotheses are examined via the logical-critical analytic method in light of these two interpretations and by the assumption of non-authorization of the unfeasible duty and the exclusion of any unfeasible duty. The purpose of the present research is to critically apply the principle of the feasible duty to a varied range of applied ethics.