The Quality of Darkness
Tamas ('darkness,' 'inertia') is the third of the three guṇas. It is the quality of heaviness, opacity, inertia, confusion, and delusion. When tamas predominates, a person experiences ignorance, torpor, carelessness, excessive sleep, inability to discriminate between the real and unreal, and deep attachment to comfort and routine.
Effects of Tamas
Tamasic food (stale, overprocessed, or intoxicating food) increases tamas. Tamasic associations (with the spiritually careless) deepen it. Tamasic activity is characterized by laziness, procrastination, and avoidance of both action and inquiry. The Bhagavad Gītā (14.13) notes that when tamas is dominant, even the light of knowledge is obscured and one lives in delusion (moha), heedlessness (pramāda), and confusion (mūḍhatā).
Tamas and Avidyā
In Vishishtadvaita, tamas at the cosmological level is the state of Prakṛti in its undifferentiated (avyakta) form before creation — a kind of primordial opacity. At the individual level, tamas corresponds to deep avidyā — the fundamental ignorance about the self's nature and about Brahman. Reducing tamas is thus inseparable from the process of knowledge and devotion.
Overcoming Tamas
The remedy for tamas is a combination of sattva-increasing practices — company of devotees (satsaṅga), study of śāstra, regular worship (tiruvaradhana), and Divya Prabandham recitation — and rajas-transforming practices that introduce activity and inquiry where there was passivity and ignorance.