Scientists may study mainly matter but they cannot ignore the human mind, or consciousness: spiritual practitioners may be engaging mainly in developing the mind but they cannot completely ignore their physical needs. It is for this reason that I have always stressed the importance of combining both mental and the material approach to achieving happiness for humankind.
Internal peace is an essential first step to achieving peace in the world. How do you cultivate it? It's very simple. In the first place by realizing clearly that all mankind is one, that human beings in every country are members of one and the same family.
We know that to wage a nuclear war today, for example, would be a form of suicide; or that to pollute the air or the oceans in order to achieve some short-term benefit would be to destroy the very basis for our survival.