IV. (14) Silence, then, is a desirable thing for those who are ignorant, but for those who desire knowledge, and who have at the same time a love for their master’s freedom of speech, is a most necessary possession. Accordingly it is said, in the book of Exodus, “The Lord will fight for us, and you will be Silent.”{5}{#ex 14:4.} And, immediately afterwards, there is added a scripture in the following words: “And the Lord said unto Moses, Why dost thou cry unto me?” As it is proper for those persons to be silent who can say nothing worthy of being listened to, and for those to speak who, through love of wisdom, believe in God; and not only to speak quietly but to cry out with exceeding noise, not indeed with the noise of the mouth and tongue, by means of which they say that the air is affected with a rotatory motion, and so is rendered capable of being perceived by the hearing, but by the all-instructed and very loudly speaking organ of that voice of which no mortal man is the hearer, but only the uncreated and immortal God. (15) For the well-arranged and carefully attuned melody of that harmony which is perceptible by the intellect, the invisible musician, perceptible by the intellect, is alone able to comprehend; but no one of those involved in the entanglements of the outward senses can appreciate it. Accordingly, when the entire organ of the mind sounds according to the symphony of the diapason and of the double diapason, the hearer, as it were, asks (for he does not ask in reality, since everything is known to God), “Why dost thou cry unto me?” Is it in supplications that evils may be averted, or in thankfulness for a participation in good things which have been already enjoyed, or for a combination of both reasons?