In Jainism, "Santati Palan" (literally 'continuity maintenance') refers to the period during which living beings could maintain their bodily existence with utmost ease, implying longevity, health, and minimal suffering. This concept is closely linked with the Jain theory of Time (Kāl), which is cyclical and divided into two equal halves: Utsarpini (ascending) and Avasarpini (descending), each consisting of six "āras" (epochs).

The Fourth Āra (Dukhama-Sukhamā or Dukhama Sukhamā Kāla):

• The fourth āra is known as "Dukhama-Sukhamā" (period of happiness mixed with misery).
• According to Jain texts, in the fourth āra, the capacity of beings to easily maintain their bodily continuity (Santati Palan) starts diminishing compared to the previous (third) āra.
• Lifespans, stature, strength, and the ease of living continue to decrease as the āra progresses.
• Specifically, the average lifespan in the fourth āra is described as ranging from several thousand years at the beginning, steadily declining as the era moves forward.
• By the end of the fourth āra, human life span, strength, and the ability for Santati Palan reduce drastically, and suffering increases.
• In the current time cycle (Avasarpini), we are believed to be in the fifth āra, in which Santati Palan is much more difficult, and human life span is much shorter (maximum 120 years as per Jain scriptures).

Summary Table (as per Jain texts):

| Āra | Santati Palan (Bodily Continuity) | Human Lifespan | |--------------|-----------------------------------|--------------------------| | 3rd (Sukhamā)| Very easy, extremely long | 84,000 years and more | | 4th (Dukhama-Sukhamā) | Decreases steadily | Several thousand years to 100 years | | 5th (Dukhama)| Very difficult, short lifespan | Maximum 120 years |

References:

• Jain Agamas (e.g., Tiloya Panatti)
• "Jainism: The World of Conquerors" by Natubhai Shah
• "Jain Darshan" by Jinendra Varni

If you would like more details about the characteristics of the fourth āra or Santati Palan, or about Jain cosmology, please let me know!