According to your letter, epidemics have been widespread recently. They say that human beings have two kinds of sickness. First, our bodies get sick. Our bodies consist of the four elements: earth, water, fire and wind. As each of the four elements has 101 sicknesses, our bodies have a total of 404 sicknesses. These physical sicknesses do not necessarily depend on the Buddha to be cured. There is no physical sickness that cannot be cured by the medicine prepared by such famed physicians as Jisui, Rusui, Jivaka and P’ien-ch’üeh.

In the second place, our minds get sick in a vast number of ways. Beginning with the three poisons of greed, anger and stupidity, sickness in our minds totals as many as 84,000. Even the two heavenly beings and three hermits or the six non-Buddhist masters in India could not cure them, not to speak of the medicines administered by such sage rulers of ancient China as Shen-nung and the Yellow Emperor.

Toki Nyūdō-dono Go-henji: Chibyō-shō, A Response to Lay Priest Lord Toki: Treatise on Healing Sickness, Writings of Nichiren Shōnin, Doctrine 2, Page 252