18.31 यया by which, धर्मम् Dharma, अधर्मम् Adharma, च and, कार्यम् what ought to be done, च and, अकार्यम् what ought not to be done, एव even, च and, अयथावत् wrongly, प्रजानाति understands, बुद्धिः intellect, सा that, पार्थ O Partha, राजसी Rajasic (passionate).Commentary: There is no proper eivalent in the English language for the word Dharma. Duty, righteousness, virtue, law are very poor translations of the word. That which elevates you and takes you to the goal, i.e., Brahman or the Self, is Dharma. That which hurls you down into the dark abyss of ignorance is Adharma. What is ordained in the scriptures is Dharma what is prohibited by them is Adharma. A Rajasic intellect is not able to distinguish between right and wrong or to understand the difference between righteous and unrighteous actions.Ayathavat Wrongly Contrary to what is determined by all authorities or men of wisdom or to the highest knowledge.