Even the intelligent are bewildered in determining what is action and what is inaction. Now I shall explain to you what action is, knowing which you shall be liberated from all misfortune. The intricacies of action are very hard to understand. Therefore one should know what action is, what forbidden action is, and what inaction is.
The confidential truth about what constitutes good action is almost impenetrable. Some hold that good action consists of executing one's social responsibilities. This is what common men generally understand by good action. But a few verses after the ones quoted above, Lord Kṛṣṇa uses the phrase brahma-karma to describe good action, and the word brahma points to Brahman. Therefore some say work done on the platform of Brahman is good action. Others say that good action includes works beneficial for the self, the society, the nation, and humanity at large. When a person acts with such lofty intentions, he is surely known as a good man. Indeed, his actions are certainly noble compared with those of persons with warped mentalities. This kind of action is not buddhi-yoga, however, because such philanthropic works can at best replace one set of people's mundane desires with a new set, but they can never completely root out these unwanted desires from within the heart. Philanthropic activities cannot prepare us for unalloyed devotional service, which is uncontaminated by empirical knowledge and fruitive action.
Individual material cravings are less harmful to the world than mass movements for sense gratification. If the material desires of an individual are unfulfilled, he certainly becomes depressed, but when the mass of people remain dissatisfied, the distress is much greater and gives rise to social conflict. In any case, mundane yearnings bring suffering, both individual or collective. Even if a person starts out not intending enjoy the fruits of his actions, once those fruits come he is forced to enjoy them because he thinks of himself as the doer, influenced as he is by the three modes nature - goodness, passion, and ignorance. These fruits are not without the bitter seeds of anxiety, entanglement, frustration, and disruption. Therefore, neither the execution of social responsibilities nor philanthropic work is ultimately good action. Devotional service to the Supreme Lord, which is beyond the three modes, must be accepted as the only good action.
The noble Arjuna thoroughly analyzed what was good and bad, what was his duty and not his duty, and decided not to take up arms to fight. Then Lord Kṛṣṇa, understanding that Arjuna was motivated by self-gratificatory social sentiments and sheer selfish interests, gave him two kinds of instructions: The first dealt with the process by which the conditioned jīva attains liberation; the second taught Arjuna how the liberated soul can surrender to the Lord and render pure devotional service. Authorized scriptures like Bhagavad-gītā contain the transcendental teachings of the Lord Himself or of self-realized personalities. These scriptures are free from the four human frailties, that is, illusion, mistakes, limited senses, and the cheating propensity. Thus the scriptural injunctions have always remained pristine, despite childish attempts by imperfect men to distort them. Such scriptural instructions not only teach self-control and the elevation of consciousness, but they also help rid us of false ego, bring us to the stage of goodness, and offer us ultimate liberation.