The energy of sattva and rajas is present in tamas, only it is locked up, potential. The more tamas is heated, the more power is released. As tamas melts, a tremendous stream of energy pours into our lives.
Easwaran argues that tamas is not mere absence but imprisoned energy, and that spiritual practice works precisely by converting this latent potential into active, purposive force.
, The Bhagavad Gita for Daily Living: A Verse-by-Verse Commentary, 1975thesis