Tree of the knowledge of good and evil

"When we have torn off the coatings of this life's perishable leaves, we must stand again in the sight of our Creator; and repelling all the illusion of taste and sight, take for our guide God's commandment only, instead of the venom-spitting serpent. That commandment was, to touch nothing but what was Good, and to leave what was evil untasted; because impatience to remain any longer in ignorance of evil would be but the beginning of the long train of actual evil. For this reason it was forbidden to our first parents to grasp the knowledge of the opposite to the good, as well as that of the good itself; they were to keep themselves from "the knowledge of good and evil," and to enjoy the Good in its purity, unmixed with one particle of evil."