Sāṅkhya: Categories of the Absolute Truth and the Unfolding of Creation
Tattva-vicāra
द्योतनं पचनं पानमदनं हिममर्दनम् । तेजसो वृत्तयस्त्वेता: शोषणं क्षुत्तृडेव च ॥ ४० ॥
dyotanaṁ pacanaṁ pānam adanaṁ hima-mardanam tejaso vṛttayas tv etāḥ śoṣaṇaṁ kṣut tṛḍ eva ca
Fire is known by its light, by cooking and digestion, by destroying cold, by drying and evaporation, and by arousing hunger and thirst, which lead to eating and drinking.
The first symptoms of fire are distribution of light and heat, and the existence of fire is also perceived in the stomach. Without fire we cannot digest what we eat. Without digestion there is no hunger and thirst or power to eat and drink. When there is insufficient hunger and thirst, it is understood that there is a shortage of fire within the stomach, and the Āyurvedic treatment is performed in connection with the fire element, agni-māndyam. Since fire is increased by the secretion of bile, the treatment is to increase bile secretion. The Āyurvedic treatment thus corroborates the statements in Śrīmad-Bhāgavatam. The characteristic of fire in subduing the influence of cold is known to everyone. Severe cold can always be counteracted by fire.
In this verse, Lord Kapila explains that tejas manifests as illumination, cooking/digestion, consuming, dispelling cold, drying, and even as the experiences of hunger and thirst.
Because hunger and thirst arise from the body’s internal fire and its transformative power—tejas governs digestion, assimilation, and drying, so these sensations are counted among its functions.
It encourages mindful respect for the body’s digestive fire—balanced habits, proper diet, and regulated living—while remembering that these bodily processes are material functions distinct from the soul.