I mean, I’m perfectly satisfied with my explanation from upthread. It’s not definitive but it seems self-consistent and self-contained within Genesis.
- The purpose of the Garden is to collect all kinds of trees that are pleasing to the sight and good for food. (Genesis 2:9)
- The Tree of Knowledge is a kind of tree that is good for eating and a delight to the eyes. (Genesis 3:6)
Like all explanations of literally anything, you could follow up with a “why” question (“why does the Garden have that purpose?”, “why place the Tree of Knowledge in the middle of the garden?”; see also “why is the sky blue?”, “why does the short end of the visible spectrum appear blue?”, and “why are S-cones sensitive to shorter wavelengths?”). But regarding the question of immediate purpose, I find this explanation satisfactory.
I have to speculate more to answer the followup questions.
Why is the Tree of Knowledge in the middle of the Garden of Eden?
The Tree of Life is also located in the middle of the Garden (Genesis 2:9), so I infer with some confidence that the Tree of Life and the Tree of Knowledge share a common property which merits their central placement. What do these two trees have that other trees do not?
A) Magic Fruits
According to one predominant interpretation the fruits have special properties: the fruits of the Tree of Life bestow eternal life (Genesis 3:22) while the fruits of the Tree of Knowledge are a source of wisdom (Genesis 3:5-7). These special properties set the two trees apart from all other trees and merit their central placement in the Garden of Eden.
Genesis 2:9
And from the ground God caused to grow every tree that was pleasing to the sight and good for food, with the tree of life in the middle of the garden, and the tree of knowledge of good and bad.
Genesis 3:4-5
And the serpent said to the woman, “You are not going to die, but God knows that as soon as you eat of it your eyes will be opened and you will be like divine beings who know good and bad.”
Genesis 3:6-7
When the woman saw that the tree was good for eating and a delight to the eyes, and that the tree was desirable as a source of wisdom, she took of its fruit and ate. She also gave some to her husband, and he ate.
Then the eyes of both of them were opened and they perceived that they were naked; and they sewed together fig leaves and made themselves loincloths.
Genesis 3:22
And God said, “Now that humankind has become like any of us, knowing good and bad, what if one should stretch out a hand and take also from the tree of life and eat, and live forever!”
Or, No Magic Fruits
There is an alternative interpretation which says, rather than the fruits having any magical properties, they were simply normal fruits. Maybe a fig or etrog. “[T]he eyes of both of them were opened” (Genesis 3:7) refers to the first realization of wrongdoing, by virtue of having violated a divine command (Genesis 2:17). The fruit was simply a catalyst for the first human experiences of shame and self-consciousness (Genesis 3:7-10) and punishment (Genesis 3:16-19), and thus the first human understanding of morality (good and evil).
This interpretation warrants a re-evaluation of the temptation of Eve,
Genesis 2:16-17
And God commanded the Human, saying, “Of every tree of the garden you are free to eat; but as for the tree of knowledge of good and bad, you must not eat of it; for as soon as you eat of it, you shall die.”
Genesis 3:4-5
And the serpent said to the woman, “You are not going to die, but God knows that as soon as you eat of it your eyes will be opened and you will be like divine beings who know good and bad.”
In the former interpretation where the fruits had the magical property of bestowing knowledge, the serpent spoke the plain truth. And this is a strong point against that interpretation, because Eve’s impression was that the tree was itself a source of wisdom (Genesis 3:6); Eve later told God she had been duped (Genesis 3:13) which implies that the tree had no magical properties after all.
Genesis 3:6
When the woman saw that the tree was good for eating and a delight to the eyes, and that the tree was desirable as a source of wisdom, she took of its fruit and ate. She also gave some to her husband, and he ate.
Genesis 3:13
And God said to the woman, “What is this you have done!” The woman replied, “The serpent duped me, and I ate.”
Under this interpretation, where the fruits lack magical properties, the serpent deserves credit for its cleverness. Technically, the serpent is correct when it says “your eyes will be opened and you will be like divine beings who know good and bad”. But the statement was grossly misleading. Overall this I think this interpretation fits the narrative of Genesis better, which goes out of its way to mention the serpent’s cunning (Genesis 3:1).
But simply refuting the magical fruit interpretation does not answer the question of why the Tree of Knowledge is placed in the center of the Garden.
B) The Tree is a Test
Perhaps the Tree of Knowledge was placed in the middle of the Garden of Eden as a test for humankind? By placing the Tree of Knowledge in the center of the Garden, the test is put front and center.
This rationale could be either compatible or incompatible with the magical fruits interpretation. This interpretation seems to have some currency in the Christian world, mostly drawing on Biblical sources outside of Genesis.
Naturally one wonders, what purpose did God have in testing Adam and Eve if He is all-knowing? Which leads to the classic theological debates on free will, destiny, and the omniscience of God - all of which and much more must be resolved to answer the question. I don’t believe you will find anyone doing so based solely on Genesis.
C) Convenience, Aesthetics, or Utility
Assume that God created a Garden of various trees pleasing to the eyes and good for eating because He planned to take advantage of those good looks or good eats, either personally, or via other heavenly beings (i.e. angels).
This could be compatible with the magical fruits interpretation.
Closely examine the language used by the serpent and by God when describing the benefits of the Trees of Life and Knowledge,
Genesis 3:4-5
And the serpent said to the woman, “You are not going to die, but God knows that as soon as you eat of it your eyes will be opened and you will be like divine beings who know good and bad.”
Genesis 3:22
And God said, “Now that humankind has become like any of us, knowing good and bad, what if one should stretch out a hand and take also from the tree of life and eat, and live forever!”
Genesis 3:23-24
So God banished humankind from the garden of Eden, to till the humus from which it was taken: it was driven out; and east of the garden of Eden were stationed the cherubim and the fiery ever-turning sword, to guard the way to the tree of life.
Take care not to stumble into pitfalls from the translation process, but note that most commentators agree that there do exist divine beings (angels). Mostly based on other biblical sources, there are varying accounts of the relationship between God and these divine beings, and particularly, of the necessity or propensity either to consume or otherwise derive benefit from food.
On the part of God, Genesis testifies to the fact that he accepts (or at least accepted) offerings (Genesis 4). We can speculate whether God derives utility or satisfaction from the fruits of the Tree of Knowledge; however, note that he appears to reject Cain’s offerings of fruits of the soil (Genesis 4:3-5).
On the part of divine beings, consider the three divine agents through whom God visits Abraham and prophesies the birth of Isaac. The narrative goes into some detail as to the preparation of their food, and explicitly tells of their eating it (Genesis 18:5-8). Two messengers of God visit Sodom and are recieved by Lot. These two are said to consume food as well (Genesis 19:3).
Genesis 18:8
He took curds and milk and the calf that had been prepared and set these before them; and he waited on them under the tree as they ate.
Genesis 19:3
But he urged them strongly, so they turned his way and entered his house. He prepared a feast for them and baked unleavened bread, and they ate.
There is some debate to have as to whether these angels are wholly divine beings, or if there is some distinction between being a vessel or avatar of God versus a cherubim. One also notes that none of these are described as actually eating fruit of a tree. In order to conclude that divine beings derive benefit from fruit, one must still make a significant leap of faith.
But once you assume divine beings do derive benefit from fruits, it is easy enough to speculate that the placement of the Tree of Knowledge in the middle of the Garden of Eden is expressly for their benefit. The placement might be aesthetically pleasing, or it might make it more convenient to access those particular fruits. This is especially relevent if the fruits of the Trees of Life and Knowledge have magical properties.
C) Other Arguments
The Garden of Eden is the source of four rivers, and it might be that these particular trees by their nature are better suited near the convergence of the rivers. Or supposing the center of the Garden is of higher elevation (hence how the rivers flow outward), this particular tree may be better suited for the higher elevation. They could also have simply been the first trees grown, and the garden was designed around them.
~Max