Bhagavad Gita: Chapter 18, Verse 32

अधर्मं धर्ममिति या मन्यते तमसावृता |
सर्वार्थान्विपरीतांश्च बुद्धि: सा पार्थ तामसी || 32||

adharmaṁ dharmam iti yā manyate tamasāvṛitā
sarvārthān viparītānśh cha buddhiḥ sā pārtha tāmasī

adharmam—irreligion; dharmam—religion; iti—thus; yā—which; manyate—imagines; tamasa-āvṛitā—shrouded in darkness; sarva-arthān—all things; viparītān—opposite; cha—and; buddhiḥ—intellect; sā—that; pārtha—Arjun, the son of Pritha; tāmasī—of the nature of ignorance

adharmam dharmam iti ya manyate tamasavrita
sarvarthan viparitansh cha buddhih sa partha tamasi

Translation

BG 18.32: That intellect which is shrouded in darkness, imagining irreligion to be religion, and perceiving untruth to be the truth, is of the nature of ignorance, O Parth.

Commentary

The tāmasic intellect is without the illumination of sublime knowledge. Hence, it misconstrues adharma to be dharma. For example, a drunk is attached to the inebriation that drinking alcohol provides. Hence, his poor intellect, covered with the fog of darkness, cannot even perceive the sheer ruin that he brings onto himself, and he does not even mind selling his property to get his next bottle. In the tāmasic intellect, the faculty of judgment and the ability for logical reasoning become lost.