XXVII. (100) And as to the manner in which the mind becomes accursed upon the earth, he adds further information immediately afterwards, saying: "The earth which opened her mouth to receive the blood of thy brother." For it is very difficult for the mouths of the outward senses to be opened and widened, as even when they are not open the flood of the objects appreciable only by them rushes in like an overflowing river, nothing being capable of resisting their evident impetuosity; for then the mind is found to be overwhelmed, being wholly absorbed by so vast a wave, and being utterly unable to swim against it, or even to raise its head above it; (101) but it is necessary to employ all these things not so much for whatever objects can possibly be effected, but for those that are best; for the sight can perceive all colours and all shapes; but still it ought to behold only things worthy of light, and not of darkness. Again, the ear can receive all kinds of sounds; but some it ought to disregard; for myriads of the things that are said are disgraceful. Nor, O foolish and arrogant man, because nature has given you the faculty of taste, ought you to fill yourself insatiably with everything, like a cormorant; for there are many things not merely among such as are nutritious, but of those which are exceedingly so, which have, nevertheless, produced diseases accompanied with great suffering. (102) Nor does it follow that, because for the sake of the perpetuation of your race you have been endowed with the powers of generation, you ought to pursue pollutions and adulteries and other impure connections; but only such as, in a legitimate manner, engender and propagate the race of mankind. Nor, because you have been made endowed with a mouth and a tongue and the organs of speech, ought you to say everything and to reveal what ought not to be spoken, for there are times when to hold one's peace is useful. And, in my opinion, those who have learnt to speak have also learnt to be silent, the same capacity teaching a man both lines of conduct. But those men who relate what they ought not, do not display the faculty of eloquence, but the weakness of their faculty of silence. (103) On which account we labour to bind each of the mouthpieces of the senses beforementioned with the imperishable bonds of temperance. "For whatever is not bound with a bond," says Moses, in another passage, "is Impure,"[Nu 19:15.] as if the cause of its unhappiness was the fact of the parts of the soul being relaxed and open and dissolved; but that the fact of their being compacted and tightly bound together contributed to goodness and soundness of life and reason.
He, therefore, curses the godless and impious Cain with deserved curses; because, having opened the caverns of this concrete creature, he opened his mouth for all external things, praying to receive them in an insatiable manner and to contain them, to the utter destruction of the Godloving doctrine, Abel.