Tamas

It is the third grade in the guṇa in the mode of the Samkhya thought. Tamas means: darkness, darkness, heaviness, inertia. These three guṇa, independent in themselves, become entangled endlessly in the differentiated nature and their reciprocal action command the evolution of matter.
It is important to cultivate each guṇa initially, and then to find the equilibrium of the three qualities.