After speaking about conception and action in three modes, Krishna describes how one’s motivation, discernment, and conviction can be in three modes.

Krishna describes a variety of motivations driving a performer influenced by the modes of material nature.

Free from attachment (mukta-saṅgo) and false ego (anahaṁ-vādī), accompanied by conviction and enthusiasm (dhṛty-utsāha-samanvitaḥ), and unwavering (nirvikāraḥ) in success and failure (siddhy-asiddhyor), a performer (kartā) is said to be (ucyate) in the mode of goodness (sāttvika). (BG 18.26)

Attached [to action and the fruit of action] (rāgī), desiring to enjoy the fruit of action (karma-phala-prepsur), greedy (lubdho), envious (hiṁsātmako), impure (aśuciḥ), and filled with joy and sorrow (harṣa-śokānvitaḥ), a performer (kartā) is declared to be (parikīrtitaḥ) in the mode of passion (rājasaḥ). (BG 18.27)

Improperly engaged (ayuktaḥ), materialistic (prākṛtaḥ), obstinate (stabdhaḥ), deceitful (śaṭho), malicious (naiṣkṛtiko), lazy (alasaḥ), morose (viṣādī) and procrastinating (dīrgha-sūtrī ca), a performer (kartā) is said to be (ucyate) in the mode of darkness (tāmasa). (BG 18.28)

What are the qualities a performer of action exhibits while carrying out the action? These are expressed in terms of the performer’s discernment and conviction in three modes during the performance of the action. Let’s hear (śṛṇu) of the divisions (bhedaṁ) of discernment and conviction (buddher dhṛteś caiva), according to the three modes of material nature (guṇatas tri-vidhaṁ) as described (procyamānam) in full (aśeṣeṇa) in different ways (pṛthaktvena). (BG 18.29)

The quality of discernment (buddhiḥ) which (yā) carries the understanding (vetti) of what is to be engaged in (pravṛttiṁ ca) and what is to be refrained from (nivṛttiṁ ca), what is one’s duty and what is not one’s duty (kāryākārye), what is to be feared and what is not to be feared (bhayābhaye), what is binding and what is liberating (bandhaṁ mokṣaṁ ca), that is (sā) in the mode of goodness (sāttvikī). (BG 18.30)

The quality of discernment (buddhiḥ) by which (yayā) one imprecisely (ayathāvat) understands (prajānāti) righteousness and unrighteousness (dharmam adharmaṁ ca), what is one’s duty and what is not one’s duty (kāryaṁ cākāryam eva ca), that is (sā) in the mode of passion (rājasī). (BG 18.31)

The quality of discernment (buddhiḥ) which (yā), covered by darkness (tamasāvṛtā) considers (manyate) unrighteousness as righteousness (adharmaṁ dharmam iti) and takes every meaning (sarvārthān) in an opposite way (viparītāṁś ca), that is (sā) in the mode of darkness (tāmasī). (BG 18.32)