score:5
Thanissaro Bhikkhu said the other Brahma viharas are applications of Metta, and that is why Metta is the core focus in the practice.
Of these four emotions, goodwill (metta) is the most fundamental. It's the wish for true happiness, a wish you can direct to yourself or to others. Goodwill was the underlying motivation that led the Buddha to search for awakening and to teach the path to awakening to others after he had found it.
The next two emotions in the list are essentially applications of goodwill. Compassion (karuna) is what goodwill feels when it encounters suffering: It wants the suffering to stop. Empathetic joy (mudita) is what goodwill feels when it encounters happiness: It wants the happiness to continue. Equanimity (upekkha) is a different emotion, in that it acts as an aid to and a check on the other three. When you encounter suffering that you can't stop no matter how hard you try, you need equanimity to avoid creating additional suffering and to channel your energies to areas where you can be of help. In this way, equanimity isn't cold hearted or indifferent. It simply makes your goodwill more focused and effective.
http://www.accesstoinsight.org/lib/authors/thanissaro/headandheart.html
Upvote:1
In order to be able to practice Brahmavihara, First you need to get your Metta.
How to get Metta? First you need to be happy, if you're not happy, you won't be able to give your happy feeling to others.
Think about Happy Feeling and send those feeling to a friend [same gender / not family/ alive] . Try to stay with object for at least 30 mins till an hour. Then you'll realized that you don't feel your body, can't stop smiling and there's something around your head.
Then you'll send to some friends then some families then some random peoples then all of your enemies. After this you'll get your metta and you can start radiating it to your surroundings.
Once you got your metta, send it to every directions. 6 Directions as described in the suttas. Then you'll realized that you're in a very big space, with metta and an infinite space, you'll experienced karuna.
Then it changed into Mudita then Uppekha then bla bla bla until Everything Ceased.
Brahmavihara is the easiest object that even an 8 years old kid could get into arupas.
Upvote:3
The scriptures generally mention the practise of all four brahma vihara together.
As for your 2nd question, I suppose the brahma vihara are dependent upon metta. If there is no friendliness & goodwill towards others, the other brahma vihara cannot be cultivated.