"When we start to live a virtuous life, we create order in our relationship to others. Then the mind becomes extraordinarily quiet, naturally silent" ~Jiddu Krishnamurthi
I think this is why most spiritual traditions recommend precepts such as vegetarianism and honesty. Until we develop the wisdom to discern for ourselves, these general guidelines serve us very well. For example, the purpose of relationships is to share our gifts with others. If instead of this we focus on what we can get from others, our mind will not be at peace. If however, we act rightly, we will find our mind becoming silent. Just as it naturally becomes silent once we have completed some work or task or accomplished a hard-won goal.