''The Deva is capable of a high self-transforming sattwic action, the Asura incapable. We must see what is the object of this preface and the precise bearing of this distinction. The general nature of all human beings is the same, it is a mixture of the three gunas; it would seem then that in all there must be the capacity to develop and strengthen the sattwic element and turn it upward towards the heights of the divine transformation.
That our ordinary turn is actually towards making our reason and will the servants of our rajasic or tamasic egoism, the ministers of our restless and ill-balanced kinetic desire or our self-indulgent indolence and static inertia, can only be, one would imagine, a temporary characteristic of our undeveloped spiritual being, a rawness of its imperfect evolution and must disappear when our consciousness rises in the spiritual scale. But we actually see that men, at least men above a certain level, fall very largely into two classes, those who have a dominant force of sattwic nature turned towards knowledge, self-control, beneficence, perfection and those who have a dominant force of rajasic nature turned towards egoistic greatness, satisfaction of desire, the indulgence of their own strong will and personality which they seek to impose on the world, not for the service of man or God, but for their own pride, glory and pleasure.
These are the human representatives of the Devas and Danavas or Asuras, the Gods and the Titans. This distinction is a very ancient one in Indian religious symbolism.
The fundamental idea of the Rig Veda is a struggle between the Gods and their dark opponents, between the Masters of Light, sons of Infinity, and the children of Division and Night, a battle in which man takes part and which is reflected in all his inner life and action. This was also a fundamental principle of the religion of Zoroaster.
The same idea is prominent in later literature. The Ramayana is in its ethical intention the parable of an enormous conflict between the Deva in human form and the incarnate Rakshasa, between the representative of a high culture and Dharma and a huge unbridled force and gigantic civilisation of the exaggerated Ego.
The Mahabharata, of which the Gita is a section, takes for its subject a lifelong clash between human Devas and Asuras, the men of power, sons of the Gods, who are governed by the light of a high ethical Dharma and others who are embodied Titans, the men of power who are out for the service of their intellectual, vital and physical ego.
The ancient mind, more open than ours to the truth of things behind the physical veil, saw behind the life of man great cosmic Powers or beings representative of certain turns or grades of the universal Shakti, divine, titanic, gigantic, demoniac, and men who strongly represented in themselves these types of nature were themselves considered as Devas, Asuras, Rakshasas, Pisachas.
The Gita for its own purposes takes up this distinction and develops the difference between these two kinds of beings, "dvau bhutasargau".
It has spoken previously of the nature which is Asuric and Rakshasic and obstructs God-knowledge, salvation and perfection; it now contrasts it with the Daivic nature which is turned to these things.
Arjuna, says the Teacher, is of the Deva nature. He need not grieve with the thought that by acceptance of battle and slaughter he will be yielding to the impulses of the Asura. The action on which all turns, the battle which Arjuna has to fight with the incarnate Godhead as his charioteer at the bidding of the Master of the world in the form of the Time-Spirit, is a struggle to establish the kingdom of the Dharma, the empire of Truth, Right and Justice. He himself is born in the Deva kind; he has developed in himself the sattwic being, until he has now come to a point at which he is capable of a high transformation and liberation from the traigunya and therefore even from the sattwic nature.
The distinction between the Deva and the Asura is not comprehensive of all humanity, not rigidly applicable to all its individuals, neither is it sharp and definite in all stages of the moral or spiritual history of the race or in all phases of the individual evolution.
The tamasic man who makes so large a part of the whole, falls into neither category as it is here described, though he may have both elements in him in a low degree and for the most part serves tepidly the lower qualities.
The normal man is ordinarily a mixture; but one or the other tendency is more pronounced, tends to make him predominantly rajaso-tamasic or sattwo-rajasic and can be said to be preparing him for either culmination, for the divine clarity or the titanic turbulence.''
from Sri Aurobindo -Essays on the Gita