Ahimsa is a Sanskrit word for non-killing and non-harming. It is not mere passiveness, but a positive method of meeting the dilemmas and decisions of daily life. In the western world, we call it Dynamic Harmlessness. The six pillars of this dynamic philosophy for modern life (one for each letter: A-H-I-M-S-A) are:

ABSTINENCE FROM ANIMAL PRODUCTS
HARMLESSNESS WITH REVERENCE FOR LIFE
INTEGRITY OF THOUGHT, WORD, AND DEED
MASTERY OVER ONESELF
SERVICE TO HUMANITY, NATURE, AND CREATION
ADVANCEMENT OF UNDERSTANDING AND TRUTH

Ahimsa is explained in detail in Ahimsa Volume 41, Number 4, page 19.