Nicene and Post-Nicene Fathers: Series II/Volume XI/John Cassian/The Twelve Books/Book VII/Chapter 4

Chapter IV.

That we can say that there exist in us some natural faults, without wronging the Creator.

then we say that these impulses were implanted in us by the Creator, He will not on that account seem blameworthy, if we choose wrongly to abuse them, and to pervert them to harmful purposes, and are ready to be made sorry by means of the useless Cains of this world, and not by means of showing penitence and the correction of our faults: or at least if we are angry not with ourselves (which would be profitable) but with our brethren in defiance of God&#8217;s command. For in the case of iron, which is given us for good and useful purposes, if any one should pervert it for murdering the innocent, one would not therefore blame the maker of the metal because man had used to injure others that which he had provided for good and useful purposes of living happily.