The doer of works is the nexus of action. The consciousness of the ego creates the sense of separateness of the doer. Depending on the characteristics of the individual and the predominant action of any of the three Gunas, the sense of the doer takes on differing characteristics that reflect the Gunas.
Sri Aurobindo describes the action of the Gunas in relation to the “doer” of works: “The tamasic doer of action is one who does not put himself really into the work, but acts with a mechanical mind, or obeys the most vulgar thought of the herd, follows the common routine or is wedded to a blind error and prejudice. He is obstinate in stupidity, stubborn in error and takes a foolish pride in his ignorant doing; a narrow and evasive cunning replaces true intelligence; he has a stupid and insolent contempt for those with whom he has to deal, especially for wiser men and his betters. A dull laziness, slowness, procrastination, looseness, want of vigour or of sincerity mark his action. The tamasic man is ordinarily slow to act, dilatory in his steps, easily depressed, ready soon to give up his task if it taxes his strength, his diligence or his patience.”
The character of the rajasic doer is defined by the qualities of desire and greed, seeking of the fruit, whether it be wealth, fame or power of some sort or another, and characterized by violence and cruelty without regard to the needs or feelings of others in his seeking for satisfaction of his egoistic claims. “He is full of an incontinent joy in success and bitterly grieved and stricken by failure.”
“The sattwic doer is free from all this attachment, this egoism, this violent strength or passionate weakness; his is a mind and will unelated by success, undepressed by failure, full of a fixed impersonal resolution, a calm rectitude of zeal or a high and pure and selfless enthusiasm in the work that has to be done.”
There is also a status beyond that of Sattwa where the quality and nature of the doer becomes simply a point of focus for the divine Master to carry out his Will in the development of the world and its manifestation. “At and beyond the culmination of Sattwa this resolution, zeal, enthusiasm become the spontaneous working of the spiritual Tapas and at last a highest soul-force, the direct God-Power, the mighty and steadfast movement of a divine energy in the human instrument, the self-assured steps of the seer-will, the gnostic intelligence and with it the wide delight of the free spirit in the works of the liberated nature.”
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 19, The Gunas, Mind and Works, pp. 484-485