240. Three types of buddhi and dhruti

After explaining the threefold nature of karta and karma, Krishna explains that buddhi (intellect) and dhruti (fortitude or courage) are also threefold as per gunas (18.29). He says, "The intellect is said to be satvik when it understands what is desireful action and renunciation, what is duty and what is not, fear and fearless, bondage and liberation (18.30). The intellect is considered to be rajasic when it is confused between dharma (righteousness) and adharma (unrighteousness), and cannot distinguish between kaaryam (dutiful action) and akaaryam (undutiful action) (18.31). That intellect is said to be tamasic which is enveloped in darkness, imagines adharma to be dharma and looks upon all things in a perverted way" (18.32). Our general understanding is that the nature of intellect varies from person to person as well as with time. The aforementioned verses clarify that our intellect manifests depending on the guna under whose influence we are at that point of time. Clarity is the hallmark of satva and confusion is the hallmark of tamas. Rajas keeps oscillating between clarity and confusion. Like akankaar, there is hardly any word to describe dhruti,  but is generally described as fortitude or determination. It is a subtle faculty in a person that makes them strive continuously towards a goal. It is said that dhruti makes us what we are because of our persistence on our path. About dhruti, Krishna says, "The dhruti is said to be satvik with which one regulates mind, senses, prana (life breath) through yoga (18.33). The dhruti is said to be rajasic by which one clings on to pleasures and wealth arising out of attachment and desire for rewards (18.34). The dhruti is said to be tamasic in which one does not give up dreaming, fearing, grieving, despair, and conceit" (18.35).