The Perfection of Loving-kindness - A simile for the four Brahmaviharas

We should not think that we have developed metta already sufficiently when we have slightly less anger or when we have metta for just a few people. This is not enough. When we meet other people, we should remember that we should extend to them, as the occasion demands, metta, compassion, sympathetic joy or equanimity, and that there should be no limits to their extension. We should not restrict the extension of the brahmaviharas to only particular persons. We can verify for ourselves whether we are ready further to develop the brahmaviharas and to extend them to others all the time. This is the way to live like the Brahmas.
The “Atthasalini” (Book I, Part V, Ch XIII, Divine States, 196) uses a simile for the four Brahmaviharas. Metta is like a small child, compassion is like a child who is sick, sympathetic joy is like a child who is becoming an adolescent and equanimity is like a child who manages his own affairs.
As regards loving-kindness which is like a baby, everybody wishes for his wellbeing and prosperity in growing up, but we should have lovingkindness not only for small children. Everybody is like a baby one should assist, and in this way we can feel true loving-kindness for all people. However, this is only a simile helping us to understand the characteristic of loving-kindness. Metta is like the attitude of a mother towards her child who is still a baby and needs her loving care to grow up. Likewise, we should as a loving mother support other people.
Compassion is like a sick child. A mother who has a sick child should try to take care of it so that it will be cured, so that it is free from suffering and illness. When we see other people, not only children, we wish that they are free from suffering and that is compassion. We should not limit compassion to particular people, it should be unlimited.
Sympathetic joy is rejoicing in someone else’s welfare. This is compared to the joy of parents who have a child that is becoming an adolescent and wish for the child to keep on enjoying the good things of adolescence for a long time. Equanimity is like a child who can manage his own affairs so that he is no longer a burden to his parents, and his parents do not have to exert themselves with regard to each of his actions.
If the brahmaviharas are practised in the aforesaid ways, defilements can be abandoned and panna can be developed which knows what is beneficial and what is disadvantageous. The brahmaviharas are most valuable, but we should verify for ourselves whether we truly have loving-kindness, compassion, sympathetic joy and equanimity. We should remember that the development of panna and the eradication of defilements take an endlessly long time.