Yam means self-restraint. -- In English self-restraint looks like suppressing, repressing. Self-restraint is not repression. Here self-restraint does not mean to repress oneself. It simply means to direct one's life -- not to repress the energies, but to direct, to give them a direction. These energies can be used in such a way that they can become the door for the unlimited. Because you can live such a life, which goes on moving in opposite directions, in many directions -- then you will never reach anywhere. It is just like a car: the driver goes a few miles to the north, then changes the mind; goes a few miles to the south, then changes the mind; then goes a few miles to the west, then changes the mind; and goes on this way. He will never reach anywhere. He will never have the feeling of fulfillment. You can go on moving in many ways, but unless you have a direction you are moving uselessly. You will feel more and more frustrated and nothing else.
So self-restraint simply means: to give a direction to life and be a little more centered. Direction creates the center; then the center gives direction. And they are mutually fulfilling.
Nonviolence simply means loving life in all its manifestations. Love life so much that you would not like to hurt anybody, that's all. Remember only one thing not to hurt anyone willfully. To be nonviolent means to be beneficial, to be helpful to everybody -- to yourself and to others also.
Truthfulness means authenticity, to be true -- not to use masks: to be natural and at ease anywhere be truthful to yourself. How to remain true? By not being a football of other peoples opinions, what they say for you to be: always listen to your inner voice, what you would like to be. Don't allow others to manipulate and control you.
The third is asteya nonstealing, honesty. Knowledge, things -- nothing should be stolen.
Brahmacharya. It has been translated as "sexual continence," celibacy. But sexual celibacy is a very narrow thing; it is one part of it, but not the whole of it. Brahmacharya is not against sex. It means transmutation of the energy: it is not being against sex, rather it is changing the whole energy from the sex center to the higher centers. This means: trying to understand sex energy, trying to understand how it moves in the body, trying to understand why it gives pleasure, from where pleasure really comes. When the same energy moves upwards you become a dam of energy. That is brahmacharya. You go on accumulating energy. The more you accumulate, the higher it rises.
Nonpossessiveness. For example, if you love a person: if you try to possess the person, then you don't love. And you are not certain about his love also; that's why you create all safety measures, surround him by every trick, cunningness, cleverness, so that he cannot leave you. If you really love, there is no need to possess. Sharing is the meaning of nonpossessiveness.