The āsura people know not what should be done (dharma) and what should not be done (adharma). Such people have neither cleanliness (outer and inner) nor good conduct. They are not given to truthfulness.
When an individual lives alone, he can think, speak and act in any manner. He will have no let or hindrance, nor will he cause any harm to another, for he is alone. But when two or more people begin to live together, ethics and propriety become indispensable. Whatever everyone does must conform to the standards and styles benevolent to all, and harmful to none. To feel complacent and not to be concerned about these is a sheer folly.
But the world will always have some devilish people, who have no regard for disciplines, values and standards. They care not to know what is good and auspicious, and what is not.
They have no care for cleanliness, nobility or benevolence. Little do they want to know about dharma and adharma. Why say much, they have no regard for even truth or truthfulness at all.