"An excellent method of preserving interior silence is to keep exterior silence. . . even in the world, each one of us can make his own solitude, a boundary beyond which nothing can force its way unperceived. It is not noise in itself that is the difficulty, but noise that is pointless; it is not every conversation, but useless conversations; not all kinds of occupation, but aimless occupations. In point of fact, everything that does not serve some good purpose is harmful. It is foolish, nay, more, it is a betrayal to devote to a useless objective powers that can be given to what is essential. There are two ways of separating ourselves from almighty God, quite different from one another but both disastrous, although for different reasons: mortal sin and voluntary distractions—mortal sin, which objectively breaks off our union with God, and voluntary distractions, which subjectively interrupt or hinder our union from being as close as it ought to be. We should speak only when it is preferable not to keep silence. The Gospel does not say merely that we shall have to give an account of every evil word, but of every idle thought."
— St. Alphonsus Liguori