These three modes have been given in the Sankhya system…the three names, sattva, rajas and tamas. Tamas is the principle and power of inertia; rajas is the principle of kinesis, passion, endeavour, struggle, initiation; sattwa the principle of assimilation, equilibrium and harmony.
Aurobindo provides the canonical Sankhya-Yoga definition of the three gunas as Nature’s fundamental qualitative modes and argues their primary significance is psychological and spiritual, not merely metaphysical.
, The Synthesis of Yoga, 1948thesis