BG Chap 14 - The opposite natures of goodness and ignorance
Sattva creates inactivity based on knowledge, but tamas creates inactivity based on a lack of knowledge. In the mode of goodness, by development of knowledge, one can understand what is what, but the mode of ignorance is just the opposite. Everyone under the spell of the mode of ignorance becomes mad, and a madman cannot understand what is what. Instead of making advancement, one becomes degraded. In goodness we can work purely. In passion we at least produce fruits from our work that may be offered to Kṛṣṇa. Ignorance, however, produces nothing but deeper ignorance.