In Jainism, fasting (known as upavāsa or tapas) is considered a powerful spiritual practice to shed accumulated karma (karmic particles) that bind to the soul (jīva).

Logical Explanation:

1. Nature of Karma in Jainism:

- Karma is a subtle matter that attaches to the soul due to passions (kashayas) like anger, pride, deceit, and greed, as well as through actions driven by attachment and aversion. - The more one indulges in desires and attachments, the more karma accumulates.

1. Role of Fasting:

- Fasting is a voluntary restraint from consuming food (and sometimes water). It is not just about physical abstinence, but about controlling desires, passions, and bodily urges. - By fasting, a person consciously avoids the intake of food and controls the urge to eat, which is one of the strongest instincts.

1. Reduction of Passions:

- Fasting helps to subdue passions and desires. When one overcomes hunger and thirst, it reduces attachment to bodily pleasures and comfort. - This self-control weakens the intensity of passions that are primary causes of new karmic influx (āsrava).

1. Minimizing Actions:

- During fasting, physical and mental activities are minimized. Many Jains use this time for meditation (dhyāna), repentance (pratikraman), and spiritual study (svādhyāya). - Fewer actions mean less opportunity for new karma to bind.

1. Activation of Past Karma:

- Jain scriptures state that austerities (like fasting) generate spiritual heat (tapa), which “burns” or matures previously bound karma, causing it to fall away sooner (nirjarā). - Fasting can bring dormant karma to fruition in a mild form, allowing it to be experienced and shed.

1. Accompanied by Right Attitude:

- Fasting must be done with the right intention (not for show or self-torture), with a peaceful mind and focus on spiritual purification. - This right attitude ensures that the act of fasting does not itself create new karma.

Summary: In Jain logic, fasting leads to the shedding of karma because it (1) decreases new karmic influx by controlling passions and actions, and (2) helps destroy existing karma through spiritual austerity and discipline, especially when coupled with right intention and awareness.

References:

• Tattvartha Sutra (Chapter 9: On Karma)
• Uttaradhyayana Sutra (Discourses on Austerity)
• Jain Agamas and commentaries on tapas (austerities)