तच्छिष्यवचनं श्रुत्वा व्याजहार पुनर्वसुः| श्रूयतामत्र या सोम्य! युक्तिर्दृष्टा महर्षिभिः ||३१||
[Explanation by Punarvasu] Hearing these words from his disciple, Punarvasu responded, “Hear, oh gentle one! The rationale the great sages have given in this respect is that
न नाशकारणाभावाद्भावानां नाशकारणम्| ज्ञायते नित्यगस्येव कालस्यात्ययकारणम् ||३२||
the cause of destruction of entities cannot be comprehended, because no such cause exists, just as in case of time, which is always in the process of swift movement automatically gets destroyed. Being transitory by nature, things perish even as they are born.
[Definition of chikitsa and the duty of a physician] Therapeutics therefore consists of measures or operations by way of which concordance of the tissue elements can be sustained and this (achieving concordance of tissue elements) constitutes the duty of the physician.
कथं शरीरे धातूनां वैषम्यं न भवेदिति| समानां चानुबन्धः स्यादित्यर्थं क्रियते क्रिया ||३५||
Therapy is administered with the sole objective of ensuring that no discordance prevails in tissue elements and that there is sustenance of continued concordance.