In Jain tradition, the presiding deity of a temple (Mulnayak Bhagwan) is usually decided based on a mix of scriptural tradition, local history, and practical circumstances – not by an arbitrary rule. In simple terms:

1. Type of temple being planned

- Many temples are built with the clear intention: - “This will be a temple of Shri Mahavir Swami,” or - “This will be a Parshwanath derasar,” or - “This will be a temple of a specific Tirthankar like Adinath, Shantinath, etc.” - In such cases, from the very beginning the main deity is decided by the founding Acharya / sadhu / sangh / donors.

1. Based on pratima (idol) discovered or already present

- Often, an ancient idol is found during excavation, in an old house-temple, or in a damaged/ruined derasar. - If that pratima is accepted by the Acharya and sangh as pratishthā-yogya (worthy for installation), a new temple may be built around it, and that idol becomes the Mulnayak. - Many famous Tirths (especially of Shri Parshwanath) are like this – the idol was found first, and then the temple grew around it.

1. Renovations of old temples (Jirnoddhār)

When a very old derasar is renovated: - Sometimes the same Tirthankar remains Mulnayak, and a new idol of that same Tirthankar is installed. - Sometimes, by decision of the Acharya and sangh, the Mulnayak is changed (for example, from Adinath to Parshwanath or Shantinath). Historical inscriptions show such changes at various Tirths.

1. Decision-makers: who actually decides?

Typically, it is a combined decision of: - The presiding Acharya / Guru of that Gacch or Sampradaya - The local Jain sangh / trust (mandal) - The main donors (shravaks) who are building or renovating the temple The final shasan-vidhi (ritual procedure) for pratishthā (installation) – including which Tirthankar, posture, metal/stone, size, etc. – is guided by the Acharya.

1. Spiritual considerations

While deciding the Mulnayak, they often consider: - Local faith and history (for example, the area is traditionally devoted to Parshwanath or Mahavir). - Any historical or miraculous events connected with a particular idol or Tirthankar at that place. - The desire to continue an old tradition – e.g., if for centuries that town is known as a Shantinath or Adinath Kshetra, they will usually retain that.

1. No difference in spiritual value among Tirthankars

- In Jain Siddhant, all Tirthankars are equal in omniscience and liberation. - Choosing one as Mulnayak is not because one is “higher” or “lower”, but mostly due to practical, historical and devotional reasons.

1. Differences in Digambar / Shwetambar practice

- Shwetambar Murtipujak: - Temples generally have one Mulnayak in the main garbhagriha, with many other idols of Tirthankars and devas–devis around. - Decisions are under the guidance of the Gacch Acharya (e.g., Tapāgacch, Āchārya lineage) and local sangh. - Digambar: - The same principle: one main Tirthankar (often in kayotsarga posture) as Mulnayak, others around. - The decision is guided by Digambar Munis / Āchāryas and local sangh. - The method and mantras of pratishthā differ, but the basic idea of how a presiding deity is chosen is similar: tradition + Acharya’s guidance + sangh’s devotion.

1. What about Yaksha–Yakshini, Padmavati, etc.?

- These are shāsandev–shāsandevi (attendant deities), not the Mulnayak. - Their presence is decided after deciding the main Tirthankar, based on that Tirthankar’s traditional attendant deity. - They never replace the Tirthankar as the presiding deity.

In summary: The presiding deity of a Jain temple is not fixed by a single universal rule. It is usually decided by the founding or guiding Acharya together with the local Jain community, based on the type of temple they wish to establish, any historically revered idol present or discovered there, and the long-standing tradition of that place.