This is from a larger statement by T.E. Wilder, made on the Puritanboard.
This is the point of the command in the garden, not to eat of the fruit of the tree. Adam saw that the fruit was good: that, by natural law so to speak, there was nothing wrong about eating it.
But the tree was the tree of the knowledge of good and evil. What was this knowledge? That good and evil are determined by the word of God and not by external nature (the goodness and beauty of the fruit) or by man’s internal nature (hunger, desire for nutrition, etc.). The tree, taken together with God’s command, gave this knowledge without man’s having to eat from it. Eating the fruit from the tree is not acquiring knowlege of good and evil but going against that knowledge.
Which is a way of looking at this that I had never thought of.