yayā dharmam adharmaḿ ca
kāryaḿ cākāryam eva ca
buddhiḥ sā pārtha rājasī
Translation of Bhagavad Gita 18.31
O son of Pritha, that understanding which cannot distinguish between religion and irreligion, between action that should be done and action that should not be done, is in the mode of passion.
Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:
No commentary by Srila Prabhupada.
Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:
The person of rajasika intelligence does not correctly understand (ayathavat) the distinctions.
Commentary by Sri Ramanuja of Sri Sampradaya:
18.31 That Buddhi by which one does not know exactly the twofold Dharma previously mentioned and its opposite, and what ought to be done and what ought not to be done by those intent on them in accordance with place, time and conditions — that Buddhi is Rajasika.
Commentary by Sri Sridhara Swami of Rudra Sampradaya:
Here Lord Krishna explains that the buddhi or intellect of those who have erroneous conceptions of theism and atheism and do not comprehend what is righteousness and what is unrighteousness and what they entail and have no understanding of what should be done and what should not be done according to time, place and circumstance assuming wrongly what they think they know is incorrect are situated in raja guna the mode of passion.
Commentary by Sri Madhvacharya of Brahma Sampradaya:
Deviation in the performance of prescribed Vedic activities or concocting additions to them is against the injunctions of the Vedic scriptures. They along with abstaining from performing prescribed Vedic activities are undeniably situated in raja guna the mode of passion.
Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:
Here Lord Krishna explains that buddhi or intellect of one situated in raja guna the mode of passion distorts reality and misunderstands what is right and what is wrong, what should be done and what should not be done. Performing action at the wrong time, in the wrong place, in the wrong way. What is prohibited they engage in and what is ordained they abstain from.
Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:
18.31 O Partha, sa, that; buddhih, intellect; is rajasi, born of rajas; yaya, with which; prajanati, one understands; ayathavat, wrongly, not truly, not by discerning it from all points of view; dharmam, virtue, as prescribed by the scritpures; and adharmam, vice, what is prohibited by them; [By dharma and adharma are implied the seen and the unseen results of actions as revealed by the scriptures; karya and akarya respectively refer to the actual doing of what ought to be done and the not doing of what ought not to be done.] ca eva, as also; karyam, what ought to be done; and akaryam, what ought not to be done-those very ‘duty’ and ‘what is not duty’ as stated earlier.
Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:
18.30-32 Pravrttim etc. upto Tamasi mata. Incorrectly ; not properly.
Sanskrit Shloka Without Transliteration Marks:
yaya dharmam adharmam ca
karyam cakaryam eva ca
buddhih sa partha rajasi
Sanskrit to English Word for Word Meanings:
yayā — by which; dharmam — the principles of religion; adharmam — irreligion; ca — and; kāryam — what ought to be done; ca — also; akāryam — what ought not to be done; eva — certainly; ca — also; ayathā-vat — imperfectly; prajānāti — knows; buddhiḥ — intelligence; sā — that; pārtha — O son of Pṛthā; rājasī — in the mode of passion.