Someone following Jesus Christ in the way of St Benedict will often be silent because he realizes that what he has to say is either disrespectful, gossipy, unfruitful, insulting, vulgar, unkind or detracting of others.
He will also be silent because he realizes that what he means to say is complaining or frivolous are just stupid, and to say such things is pointless.
The monastically inclined will also be increasingly silent because he realizes that what he has to say will not be heard. In the face of irrational rage, demonic lust and foolish sentimentalism, what he has to say will be, at best, ignored, and at worst a cause for persecuting him.
Finally, the one who follows St Benedict will e silent in the face of overwhelming evil. When faced with irrational, mindless forms of argument, and the foolish arrogance and pride of the world he realizes that silence is the only response.
This is, the silence of Jesus before Pilate.
He was silent because there was nothing more to be said.
Nothing could be done. This silence of resignation sounds depressing, but within it there is peace, and within it there sits the small white bird of hope.