Step 1: Understanding the Concept:
Jainism recognizes the "Pancha-Parameshtih" or the five supreme beings who have reached high levels of spiritual purity. While all are revered, only those who have completely severed their connection with the cycle of birth and death (Samsara) and shed all their karmic baggage are considered "Mukta" or liberated. The distinction between an Arhat and a Siddha is a crucial point in Jain soteriology regarding the state of "total" liberation.
Step 2: Detailed Explanation:
To understand who is truly "Mukta", we must look at the types of Karma. There are eight types of Karma, divided into four "Ghatiya" (destructive of the soul's nature) and four "Aghatiya" (non-destructive, related to the body and physical life).
1. Arhats: These are supreme beings who have destroyed the four Ghatiya Karmas. They possess infinite knowledge (Kevala Jnana) and bliss. However, they still possess a physical body (Audarika Sharira) and the four Aghatiya Karmas (Ayush, Nama, Gotra, Vedaniya). They are "Jivan-mukta"—liberated while alive—but they still reside in the world and interact with the Sangha. They are not yet "Mukta" in the final, bodiless sense.
2. Siddhas: When an Arhat reaches the end of their lifespan, they perform "Samudghata" and shed the remaining four Aghatiya Karmas. The soul, now free from every atom of matter, rises instantly to the top of the universe (Siddhashila). Siddhas have no body, no gender, no suffering, and no physical presence. They are pure consciousness. This is the state of final liberation or Moksha. Therefore, they are the only truly "Mukta Jivas".
3. Acharyas, Upadhyayas, and Sadhus: These are ascetics who are still on the path (Marga). They possess all eight types of Karma (though in a reduced state) and are still subject to rebirth. They are "Samsari" souls striving for liberation.
The definition of "Mukta" implies the absence of all "Bandha" (bondage). Since the Arhat is still "bound" to a physical body, only the Siddha represents the absolute pinnacle of liberation. In the Siddha state, the soul remains in eternal, undisturbed bliss, perceiving the entire universe without being part of it.
Step 3: Final Answer:
The Siddhas are the only souls who have achieved total liberation (Moksha) by shedding all eight karmas and leaving the physical realm.