The Four Noble Truths as a limited specific teaching

Nichiren explained that the teaching of the Four Noble Truths was merely one of several specific teachings, which Shakyamuni taught in accordance with his listeners’ capacity and stage of practice:

“In the various other sutras we find [many doctrines] … the four noble truths [taught] for voice-hearers…”

In his Comparison of the Lotus Sutra with Other Sutras Nichiren clearly states that the Four Noble Truths were not dedicated to all categories of Buddha’s disciples, but merely to the immediate Voice-Hearers (Sravaka).  Nichiren further declares that:

“The Lotus Sutra is entirely different. It was preached equally for all [people]”. Both Suffering and Joy are facts of life

While the Four Noble Truths focuses on “sufferings” as the essential fact in life - in his letter Happiness in this World, Nichiren states that both sufferings and joy - are facts of life:

“Suffer what there is to suffer, enjoy what there is to enjoy. Regard both suffering and joy as facts of life, and continue chanting Nam-myoho-renge-kyo. no matter what happens.

How could this be anything other than the boundless joy of the Law?” WND 1 p 681

It is the power of enlightenment to the Law of Life, operating within the individual, that sufferings in daily life can be transformed into meaningful experiences.

The Four “Natural Sufferings” of all human beings

Nichiren Buddhism teaches that all people regardless of their social position have to endure inevitable hardships and sufferings in life, being:

the “Four Natural Sufferings” are those of Young age, Sickness, Old Age and Death.

These Natural Sufferings are part of the makeup of life. They are not caused by craving or attachment to desires (which constitute the subject of the Four Noble Truths) .

Old Age, for example, is simply a natural occurrence of progression of life.  No one “desires” or “craves for” that stage of Old Age, and so is the situation with Death and Sickness, or also the suffering experienced in birth, childhood and young age. 

The Four Noble Truths is a sermon focused on craving or “attachment to materialistic desires”, as a specific introduction  -  as it does not include all causes of suffering and does not include the joy of attaining enlightenment.  It is to be respected as the first sermon of the Buddha intended only to outline his compassionate aim in transforming suffering and attaining enlightenment for all people.