It was good for food. It was also pleasant to look at. Eve knew what good was when she saw it.
Genesis 2:9 And out of the ground made the Lord God to grow every tree that is pleasant to the sight, and good for food; the tree of life also in the midst of the garden, and the tree of knowledge of good and evil.
Adam was told he could eat of every tree too. Then he was told not to eat of that one.
16 And the Lord God commanded the man, saying, Of every tree of the garden thou mayest freely eat:
17 But of the tree of the knowledge of good and evil, thou shalt not eat of it: for in the day that thou eatest thereof thou shalt surely die.
It was meant to be there. It was good. Eve wasn't hallucinating. The knowledge of good and evil would have been a good thing for them to have. God put it there, not to tempt them to sin -- God never tempts people to sin. It served a purpose.
C

rine and sodium are both deadly poisons -- separately. Yet together, they form salt -- a symbol of the holy.
Regrettably, I'd say you forgot what you read in Genesis. The tree with the forbidden fruit was part of God's works -- and every thing he had made was pronounced "very good." Eve was not hallucinating.
Genesis 1:31 And God saw every thing that he had made, and, behold, it was very good. And the evening and the morning were the sixth day.