The Peace is not of the nature of inertia, but the inertia (tamas) is a degradation of peace or rest as rajas is a degradation of divine Force. So when the physical is invited to peace and cannot receive it, it brings up inertia instead.
The Spirit is eternally at rest even in the midst of action—peace gives this spiritual rest. Tamas is a degradation of it and leads to inaction.
[Sri Aurobindo: Letters on Yoga]
