Mettā - Loving kindness
Muditā - Compassion
Karuṇā - Sympathetic joy
Upekṣā - Equanimity

These attitudes are thought to be the right or ideal way of conduct towards all living beings (sattesu samma patipatti).
In the traditional Buddhist understanding of the universe the Brahma was the divine but transient ruler of the heavens, his nature was representative of the four states. Hate was simply incompatible with this state of mind, and any who develop such a state of mind through practiced conduct and meditation may be considered an equal of Brahma (Brahma-samo).

This four states are considered abodes (vihārā) because they should be considered our natural dwelling places, not fleetingly visited on rare occasions, but our homes. Love, compassion, sympathetic joy and equanimity are also known as the boundless states (appamañña). They must remain unprejudiced and extend to everyone.

To nurture such states, which do not come naturally, it is important to keep them as subjects of methodical meditation, bhāvanā. The practical aim here is to use these sublime states to achieve dhyāna; “meditative absorption”.