In the Śrīmad-Bhāgavatam ( 1.5.17 ) Śrī Nārada Muni instructs Vyāsadeva as follows:

The purport may be understood as follows: humanity may be divided into two sections, namely, the regulated and the nonregulated. Those who are engaged simply in bestial sense gratifications without knowledge of their next life or spiritual salvation belong to the nonregulated section. And those who follow the principles of prescribed duties in the scriptures are classified amongst the regulated section. The nonregulated section, both civilized and noncivilized, educated and noneducated, strong and weak, are full of animal propensities. Their activities are never auspicious because, enjoying the animal propensities of eating, sleeping, defending and mating, they perpetually remain in material existence, which is always miserable. On the other hand, those who are regulated by scriptural injunctions and thus gradually rise to Kṛṣṇa consciousness certainly progress in life.

Those who are then following the path of auspiciousness can be divided into three sections, namely, 1) the followers of scriptural rules and regulations who are enjoying material prosperity, 2) those who are trying to find out the ultimate liberation from material existence, and 3) those who are devotees in Kṛṣṇa consciousness. Those who are following the rules and regulations of the scriptures for material happiness may be further divided into two classes: those who are fruitive workers and those who desire no fruit for sense gratification. Those who are after fruitive results for sense gratification may be elevated to a higher standard of life—even to the higher planets; but still, because they are not free from material existence, they are not following the truly auspicious path. The only auspicious activities are those which lead one to liberation. Any activity which is not aimed at ultimate self-realization or liberation from the material bodily concept of life is not at all auspicious. Activity in Kṛṣṇa consciousness is the only auspicious activity, and anyone who voluntarily accepts all bodily discomforts for the sake of making progress on the path of Kṛṣṇa consciousness can be called a perfect transcendentalist under severe austerity. And because the eightfold yoga system is directed toward the ultimate realization of Kṛṣṇa consciousness, such practice is also auspicious, and no one who is trying his best in this matter need fear degradation.