As a synthesis and harmonising teaching the Gita has taken up the challenge to reconcile the different philosophical positions that were current in its time. The first of these, the opposition of Sankhya and its focus on renunciation and Yoga with its focus on transforming works, has been reconciled with the embracing concept that renunciation is an inner status rather than an outer state.
The next set of opposing principles is represented by the practices of Vedism versus the conceptual framework of Vedantism. Sri Aurobindo describes the issue: “In the opposition of Vedism and Vedantism works, karma, are restricted to Vedic works and sometimes even to Vedic sacrifice and ritualised works, all else being excluded as not useful to salvation.” “Vedantism taking its stand on the Upanishads looked on them as only a preliminary belonging to the state of ignorance and in the end to be overpassed and rejected, an obstacle to the seeker of liberation.”
“Vedism worshipped the Devas, the gods, with sacrifice and held them to be the powers who assist our salvation. Vedantism was inclined to regard them as powers of the mental and material world opposed to our salvation (men, says the Upanishad, are the cattle of the gods, who do not desire man to know and be free); it saw the Divine as the immutable Brahman who has to be attained not by works of sacrifice and worship but by knowledge. Works only lead to material results and to an inferior Paradise; therefore they have to be renounced.”
We see here essentially a parallel debate to that between Sankhya and Yoga, but with a much more focused and essentially narrower scope. Works are circumscribed and specific to the carrying out of Vedic ritual. The Upanishads however see this as continued attachment to the results of the world and the prescription, to attain salvation or liberation, is to abandon these and focus on the higher Reality which cannot be achieved through these ritualistic forms of action.
Sri Aurobindo, Essays on the Gita, First Series, Chapter 11, Works and Sacrifice, pp. 104-105, http://www.lotuspress.com