Vain and Useless Thoughts

Too much conversation has an injurious effect upon the religious interests of the mind, in addition to what has already been said, by filling the soul with many vain and useless thoughts. All such thoughts take up more or less of the mind's attention; and just so far as it is so occupied, it is necessarily deprived of the consciousness of God's sweet and purifying presence. Such are the laws of the mind, that it cannot possibly be occupied with God and a multitude of worldly vanities at the same time.

And in addition to this, it should be remembered, that words are one of the outward signs and natural expressions of the inward passions; and whatever may be true of those of a different character, it is well understood, that the resentful or angry passions, which often interpose an obstacle to holiness, generally acquire great vigor by outward exhibitions. On the contrary it is equally well understood, that they as generally wither and die under a system of repression and silence. So that by maintaining a judicious practice of silence, we shall not only find our thoughts less liable to wander and more collected in God, than they would otherwise be; but shall also find the resentful passions, and the exciting passions generally, when thus deprived of the powerful stimulation of words, more submissive, and more perfectly under control.

— edited from  The Interior or Hidden Life (1844) Part 2, Chapter 8.