Had the intention of the Gita been to justify and support the caste system in its socio-economic form, we would have seen it in the way the Gita describes the natural work of each of the four orders; however, we see just the opposite, as the Gita focuses on the internal status more than the external function.
Sri Aurobindo describes this as he itemizes the true role and action of the Brahmin: “Calm, self-control, askesis, purity, long-suffering, candour, knowledge, acceptance and practice of spiritual truth would not ordinarily be described as a man’s function, work or life occupation. Yet this is precisely what the Gita means and says,–that these things, their development, their expression in conduct, their power to cast into form the law of the sattwic nature are the real work of the Brahmin….” The actual outer form that this action takes may find its easiest manifestation in roles reserved in the caste arrangement for the Brahmin, but the Gita clearly enunciates the principle of the inner status, not the outer role, as being the true “work” of the Brahmin.
Similarly for the Kshatriya, the Gita does not focus on government, warfare or political action, but on developed qualities that need to find their expression regardless of the outer role: “but his real work is the development, the expression in conduct, the power to cast into form and dynamic rhythm of movement the law of the active battling royal or warrior spirit.”
Sri Aurobindo underlines the fact that the description of the roles of Vaishya and Sudra, the trading and service orders, are defined by the Gita, on the contrary, by their outer roles and he indicates that this is so because those who are focused on economic and service work generally are highly focused on the external world, not the inner development, and thus, would tend to identify more closely their inner and outer being with their outer function. “That too is the reason why a commercial and industrial age or a society preoccupied with the idea of work and labour creates around it an atmosphere more favourable to the material than the spiritual life, more adapted to vital efficiency than to the subtler perfection of the high-reaching mind and spirit. Nevertheless, this kind of nature too and its functions have their inner significance, their spiritual value and can be made a means and power for perfection.”
Regardless of the role and inward competency, each individual, by identifying with and carrying out his true destined role in fulfillment of his own inner being’s force, can achieve liberation and perfection. Each individual “…can by this road rise at once towards the highest inner greatness and spiritual freedom, towards perfection, towards the liberation and fulfilment of the divine element in the human being.”
Sri Aurobindo, Essays on the Gita, Second Series, Part II, Chapter 20, Swabhava and Swadharma, pp. 497-498