Read the passage and answer the questions that follow.
Some people think that Silence is golden. Words they must use, but they have no love for them. Speech is to them a danger, a device for entangling men. They feel that all may be understood so long as nothing is said; that only in silence can one reach out to the mind and the heart be known. In the exchange of words their personalities do not expand but contract; they see the lovely procession of thought and feeling turn into a dusty and disorderly crowd of words and phrases. They see the talkers with mingled fear and contempt, stripping themselves in public, like exhibitionists. The talkers cannot understand the silent; nor can the silent explain their attitude, except in speech. This illuminates the weakness of their belief, that they must convince us of the uselessness of speech by means of speech.
The central idea of the passage is _______.