What is a “four-fold-community”?

In his book “Buddhadhamma, Natural Laws and Values for Life”,
Venerable P. A. Payutto talks of the necessary factors to be in place
for the Holy Life to be deemed successful, far-reaching, and
beneficial to the majority. A “Fourfold Community” must include:

1. “The Master (Lord Buddha) is a longstanding Elder (thera), a
person of experience who has passed through all phases of life;
2. There are bhikkhus and followers who are elders and have
expert knowledge, who have received proper training and orientation,
and are steadfast and brave; they have achieved the delights of
Dhamma from the practice of yoga, and they can present the Dhamma in
a fruitful manner. They can conquer doctrines that dispute or
speeches that oppose in a way that is in accordance with the Dhamma.
There are also intermediate and newly ordained bhikkhus and followers
who have these same abilities;
3. There are bhikkhunis and female followers who are Elders
(their) intermediates, or newly ordained, who also have these same
abilities;
4. There are male lay devotees (upasaka) without families who
lead a chaste Holy Life (brahmacari), and there are those who still
have families and engage in worldly pleasures (kamasukha); these
people also have these same abilities;
5. There are female lay devotees (upasika) without families who
lead a chaste Holy Life, and there are those who still have families
and engage in worldly pleasures; these people also have the same
abilities.

If the religion even lacks the female lay devotees who have families,
it cannot be said to be progressive, complete, and well integrates.
This statement shows that the teachings of the Buddhadamma are aimed
at all kinds of people; they are for ascetics, monks, and lay people.
In other words, they cover the whole range of society.”

~Phra Prayudh Payutto~