Norinaga Motoori

Then what is good and evil in the realm of human psychology and ethics according to the Tale of Genji? Generally speaking, those who know the meaning of the sorrow of human existence, i.e., those who are in sympathy and in harmony with human sentiments, are regarded as good; and those who are not aware of the poignancy of human existence, i.e., those who are not in sympathy and not in harmony with human sentiments, are regarded as bad.

-Tusnoda, deBary and Keene, Sources of Japanese Tradition, p.533

The purpose of the Tale of Genji may be likened to the man who, loving the lotus flower, must collect and store muddy and foul water in order to plant and cultivate the flower. The impure mud of illicit love affairs described in the Tale is there not for the purpose of being admired but for the purpose of nurturing the flower of the awareness of the sorrow of the human existence. Prince Genji's conduct is like the lotus flower which is happy and fragrant but which has its roots in filthy muddy water. But the Tale does not dwell on the impurity of the water; it dwells on those who are sympathetically kind and who are aware of the sorrow of human existence, and it holds these feelings to be the basis of the good man.

-Ibid, p.534-535