  First, pacifism may not be required of all moral agents. Thus pacifism may only be required for members of particular professions. Pacifism is often thought to be a professional obligation of certain religious vocations. But such a vocation may be thought of as a choice of conscience that is not universally required. In this version of contingent pacifism, the prohibition against violence only applies to those who take a vow or make a pledge to renounce violence and war. Within this two-tiered approach, the vow of peacefulness might be considered as a sort of supererogatory ideal that is not required of others. But it is also possible for the two-tier approach to contain an implicit condemnation of those who do not take up the higher calling of pacifism.