 When the Sattva-Rajas-Tamas are in equilibrium, no modification occurs; when one of three innate qualities is more active, the process of evolution is in action, change emerges ("Gunaparinama").These two verses are significant, states Larson, in aphoristically presenting Samkhya's doctrines of causation, relationship between "vyakta" and "avyakta", and its doctrine of what drives evolution.Samkhya-karika asserts, states Larson, that apart from the Prakriti and emergent creation, of equilibrium and evolution, exists the "Purusha" (or self, soul).