  How are the three fa themselves justified? The texts that present the theory do not say, but the Mohists probably view the third standard, benefit to society, as an application of their moral theory, which they justify by appeal to the model of Heaven, or nature. That appeal they might justify in turn by independent moral criteria such as impartiality, benevolence, and reliability, as we suggested briefly in the section on  objective standards.  Critics who reject the Mohist normative theory thus may find this fa objectionable as well. As to the second standard, what people see and hear, the Mohists offer no defense. They may have an inchoate theory of sense perception that explains why the second standard is reliable, but there is little or no discussion of such issues in early Mohist texts.  The first standard reflects a shared pattern, in the Mohists’ intellectual milieu, of appealing to ancient sage-kings or culture heroes for authority. This habit was grounded in the assumption that the ancient sage-kings were dependable ethical exemplars and, in some cases, that they were the originators of the relevant normative practices. Such appeals are to some extent defensible, as they can be thought of as an appeal to experience — to norms and practices that were found ethically and practically satisfactory by wise, fair leaders in the past. Still, later Warring States thinkers will rightly question whether policies developed under ancient social conditions remain applicable today and whether we can even be sure what those policies were.