The fourth path to attaining arahantship From the Yuganaddha Sutta, there are four paths described:


Development of insight preceded by development of tranquility
Development of tranquility preceded by development of insight
Tranquility developed in tandem with insight
Mind's restlessness concerning the Dhamma well under control


From my understanding, the first three are about vipassana (insight) and samatha (tranquility).

Questions:


How does the fourth path work? Please elaborate on the fourth path.
How does one practise that? Please provide details.
Why is vipassana and samatha not required on the fourth path?



  Ven. Ananda said: "Friends, whoever — monk or nun — declares the
  attainment of arahantship in my presence, they all do it by means of
  one or another of four paths. Which four?
  
  "There is the case where a monk has developed insight preceded by
  tranquillity. As he develops insight preceded by tranquillity, the
  path is born.  .....
  
  "Then there is the case where a monk has developed tranquillity
  preceded by insight. As he develops tranquillity preceded by insight,
  the path is born. .....
  
  "Then there is the case where a monk has developed tranquillity in
  tandem with insight. As he develops tranquillity in tandem with
  insight, the path is born. .....
  
  "Then there is the case where a monk's mind has its restlessness
  concerning the Dhamma [Comm: the corruptions of insight] well under
  control. There comes a time when his mind grows steady inwardly,
  settles down, and becomes unified &amp; concentrated. In him the path is
  born.
  
  He follows that path, develops it, pursues it. As he follows the
  path, developing it &amp; pursuing it — his fetters are abandoned, his
  obsessions destroyed.
How does the fourth path work? Please elaborate on the fourth path.

By attaining “anariya jhanas”, one can attain only ceto vimutti. Thus to achieve all of the four paths, one has to practice “ariya jhanas”. Only this second Ariya Jhana will lead to  magga phala with panna vimutti. 

The fourth path does not involve samatha meditation. It is completely a  vipassana meditation. In Pali this fourth method is called **Dhamma Uddhacca Vigghahita Maanasan”. Unlike the other three methods, it takes only a very short time to come to realization through this method, but only a highly developed person can do this. This method is not for you and I. The only Ariya Meditation that may help the ordinary folk is the Savitakka/Savicara mode of meditation. For those who are more disciplined and wiser, there is the Avitakka/Avicara mode of meditation.

How does one practise that? Please provide details.

This question can never be answered. The scriptures tell us of only 14 people who have realized nibbhana by practising this method.  Few of them that come to mind are Bahiya Dharuciraya, King Pukkusati, King’s Minister Santhathi, Arahant Dabbamallatissa, and Bhikku Kumara Kashyapa.

Why is vipassana and samatha not required on the fourth path?

This answer is there within the above explanation. These few individuals came to panna vimutti, but to come to this they never did any kind of Jhana. They never had to do samatha or vipassana meditation. Within a matter of minutes, they achieved nibbana through **Dhamma Uddhacca Vigghahita Maanasan”.

To explain this Pali term…. Uddhacca  means the tendency to be high-minded (restlessness) - It arises because of high-mindedness. Uddacca remains as a cetasika and is removed only at the Arahant stage. Uddacca is the tendency to get at least irritated when not treated as expected. But it is to be noted that the levels of mana, uddacca, avijja that an Anagami has, are at much reduced level. 

Uddhacca Vigghahita means the eradication of Uddhacca. This is the quickest way to remove all traces of the root causes - raga, dosa, and, moha. Or in other words Uddhacca Vigghahita  is the easiest way to remove lobha, dosa, and, moha (for akusala kamma), and alobha, adosa, and amoha (for kusala kamma).