Bhagavad-gītā 18.31

Explain simply

Speaker: Śrī Kṛṣṇa

यया धर्ममधर्मं च कार्यं चाकार्यमेव च ।
अयथावत्प्रजानाति बुद्धिः सा पार्थ राजसी ॥३१॥

yayā dharmam adharmaṁ ca
kāryaṁ cākāryam eva ca
ayathāvat prajānāti
buddhiḥ sā pārtha rājasī

Word for word (synonyms)

yayā
by which
dharmam
principles of religion
adharmam ca
and irreligion
kāryam
work
ca
also
akāryam
what ought not to be done
eva
certainly
ca
also
ayathāvat
not perfectly
prajānati
knows
buddhiḥ
intelligence
sā
that
pārtha
O son of Pṛthā
rājasī
in the mode of passion

Translation

And that understanding which cannot distinguish between the religious way of life and the irreligious, between action that should be done and action that should not be done, that imperfect understanding, O son of Pṛthā, is in the mode of passion.

Purport

Intelligence in the mode of passion is always working perversely. It accepts religions which are not actually religions and rejects actual religion. All views and activities are misguided. Men of passionate intelligence understand a great soul to be a common man and accept a common man as a great soul. They think truth to be untruth and accept untruth as truth. In all activities they simply take the wrong path; therefore their intelligence is in the mode of passion.

What this verse teaches

Intelligence or understanding (buddhi) in three modes

The three modes of nature, side by side Full table
GoodnessPassionIgnorance
Understanding knows what ought to be done and what ought not to be done, what is to be feared and what is not to be feared, what is binding and what is liberating 18.30 cannot distinguish between the religious way of life and the irreligious, between action that should be done and action that should not be done 18.31 considers irreligion to be religion and religion to be irreligion 18.32

Bhagavad-gītā As It Is by His Divine Grace A.C. Bhaktivedanta Swami Prabhupāda © The Bhaktivedanta Book Trust International.