." It is not, I think, "science" which the Scripture here means by "knowledge"; but I find a certain distinction, according to Scriptural use, between "knowledge" and "discernment": for to "discern" skilfully the good from the evil, the Apostle says is a mark of a more perfect condition and of "exercised senses  ," for which reason also he bids us "prove all things  ," and says that "discernment" belongs to the spiritual man  : but "knowledge" is not always to be understood of skill and acquaintance with anything, but of the disposition towards what is agreeable, -- as "the Lord knoweth them that are His  "; and He says to Moses, "I knew thee above all  "; while of those condemned in their wickedness He Who knows all things says, "I never knew you  ."
2. The tree, then, from which comes this fruit of mixed knowledge, is among those things which are forbidden; and that fruit is combined of opposite qualities, which has the serpent to commend it, it may be for this reason, that the evil is not exposed in its nakedness, itself appearing in its own proper nature -- for wickedness would surely fail of its effect were it not decked with some fair colour to entice to the desire of it him whom it deceives -- but now the nature of evil is in a manner mixed, keeping destruction like some snare concealed in its depths, and displaying some phantom of good in the deceitfulness of its exterior. The beauty of the substance seems good to those who love money: yet "the love of money is a root of all evil  ": and who would plunge into the unsavoury mud of wantonness, were it not that he whom this bait hurries into passion thinks pleasure a thing fair and acceptable? so, too, the other sins keep their destruction hidden, and seem at first sight acceptable, and some deceit makes them earnestly sought after by unwary men instead of what is good.
3. Now since the majority of men judge the good to lie in that which gratifies the senses, and there is a certain identity of name between that which is, and that which appears to be "good," -- for this reason that desire which arises towards what is evil, as though towards good, is called by Scripture "the knowledge of good and evil;" "knowledge," as we have said, expressing a certain mixed disposition. It speaks of the fruit of the forbidden tree not as a thing absolutely evil (because it is decked with good), nor as a thing purely good (because evil is latent in it), but as compounded of both, and declares that the tasting of it brings to death those who touch it; almost proclaiming aloud the doctrine that the very actual good is in its nature simple and uniform, alien from all duplicity or conjunction with its opposite, while evil is many-coloured and fairly adorned, being esteemed to be one thing and revealed by experience as another, the knowledge of which (that is, its reception by experience) is the beginning and antecedent of death and destruction.
4. It was because he saw this that the serpent points out the evil fruit of sin, not showing the evil manifestly in its own nature (for man would not have been deceived by manifest evil), but giving to what the woman beheld the glamour of a certain beauty, and conjuring into its taste the spell of a sensual pleasure, he appeared to her to speak convincingly: "and the woman saw," it says, "that the tree was good for food, and that it was pleasant to the eyes to behold, and fair to see; and she took of the fruit thereof and did eat  ," and that eating became the mother of death to men. This, then, is that fruit-bearing of mixed character, where the passage clearly expresses the sense in which the tree was called "capable of the knowledge of good and evil," because, like the evil nature of poisons that are prepared with honey, it appears to be good in so far as it affects the senses with sweetness: but in so far as it destroys him who touches it, it is the worst of all evil. Thus when the evil poison worked its effect against man's life, then man, that noble thing and name, the image of God's nature, was made, as the prophet says, "like unto vanity  ."
5. The image, therefore, properly belongs to the better part of our attributes; but all in our life that is painful and miserable is far removed from the likeness to the Divine.
 Otherwise Chap. xxi. The Bodleian ms. of the Latin version gives as the title:--"Why Scripture calls the tree, the tree of the knowledge of good and evil.'"  The reference is to Genesis 2:9 (in LXX.), where the tree is called, to xulon tou eidenai gnoston kalou kai ponerou. S. Gregory proceeds to ascertain the exact meaning of the word gnoston in the text; the eating is the "knowing," but what is "knowing"? He answers, "desiring."  Cf. Hebrews 5:14  1 Thess v. 21.  Cf. 1 1 Corinthians 2:15.  2 Timothy 2:19.  Exodus 33:12 (LXX.).  S. Matthew 7:23.  1 Timothy 6:10.  Genesis 3:5, 6 (LXX.).  Psalm 144:4 (LXX.).
 The reference is to Genesis 2:9 (in LXX.), where the tree is called, to xulon tou eidenai gnoston kalou kai ponerou. S. Gregory proceeds to ascertain the exact meaning of the word gnoston in the text; the eating is the "knowing," but what is "knowing"? He answers, "desiring."
 Cf. Hebrews 5:14
 1 Thess v. 21.
 Cf. 1 1 Corinthians 2:15.
 2 Timothy 2:19.
 Exodus 33:12 (LXX.).
 S. Matthew 7:23.
 1 Timothy 6:10.
 Genesis 3:5, 6 (LXX.).
 Psalm 144:4 (LXX.).