The word Nirvana means “extinction” and it means the eradication of all evil desires, of all passions, of all egotism, so that the flame of envy, hatred, and lust will have nothing to feed upon. This is the negative side of Nirvana.

The positive side of Nirvana consists in the recognition of truth. The destruction of evil desires, of envy, hatred, and extinction of selfishness implies charity, compassion with all suffering, and a love that is unbounded and infinite. Nirvana means extinction of lust, not of love; craving, not of life. The eradication of all that is evil in man’s heart will set all his energies free for good deeds. He is no genuine Buddhist who would not devote his life to active work and a usefulness which would refuse neither his friends nor strangers, nor even his very enemies.

The above was written by Zen master Soyen Shaku in 1896.  He was Abbot of a Zen monastery in Japan and in 1905-1906 toured the United States giving lectures about Buddhism.  His lectures and other writings were collected in the book Zen For Americans.  I first read this book when I was in undergrad and was captivated by it.