The tree of the knowledge of good and evil ( ? ; Hebrew pronunciation: [?es? hada?a? tv wara?]) is one of two specific trees in the story of the Garden of Eden in Genesis 2-3, along with the tree of life.
Genesis 2 narrates that God places the first man and woman in a garden with trees of whose fruits they may eat, but forbids them to eat from "the tree of the knowledge of good and evil." When, in Genesis 3, a serpent persuades the woman to eat from its forbidden fruit and she also lets the man taste it, God expels them from the garden and thereby from eternal life.
The phrase in Hebrew: , tov wa-ra?, literally translates as good and evil. This may be an example of the type of figure of speech known as merism, a literary device that pairs opposite terms together in order to create a general meaning, so that the phrase "good and evil" would simply imply "everything." This is seen in the Egyptian expression evil-good, which is normally employed to mean "everything." In Greek literature, Homer also uses the device when he lets Telemachus say, "I know all things, the good and the evil" (Od.20:309-10).
This interpretation may partially contradict the text itself wherein God permits the consumption of every other tree in the garden, which could indicate a variety of knowledge available to the first humans (Genesis 2:16). It is further complicated by the act of the Creation of Man, wherein God gives Adam the "breath of life" from his own divine spirit, possibly indicating that humans are endowed with special knowledge as a condition of their existence (Genesis 1:26; 2:7). The Garden of Eden might represent a state of naivete that would not be possible without an incomplete or misinformed view of the world, implying primitive knowledge (Genesis 2:8). The mandate to "subdue" the earth would not be possible without some knowledge of nature (Genesis 1:28). That humans are said to be created in God's image implies they are separate from the other animals intellectually or physically (Genesis 1:26). The fact that God speaks to the first humans but not to the other animals seems to indicate they understand language (Genesis 1:28-30). Genesis 2:19-20 refers to the invention of nouns as part of humanity's lingual development. The declaration that no animal other than Woman was found suitable as a helper to Adam could be a sign that the first man seeks an intelligent consort (Genesis 2:20).
Furthermore, the Serpent who says that eating the forbidden fruit will result in knowing "good and evil" (Genesis 3:5) is described as a trickster (Genesis 3:1) who misleads Eve about the sort of wisdom the fruit will impart (Genesis 3:6). The consumption of the fruit of the Tree of the Knowledge of Good and Evil does not result in the first humans understanding any scientific principle, but rather their vulnerability in nature, symbolized by nakedness. Adam and Eve are said to hide from God because of their nakedness, indicating that they understand their vulnerability to punishment for violating the precept (Genesis 3:10). Symbolically, the passages that follow from the eating of the fruit may refer to efforts to address their vulnerability first peacefully (fig leaves) (3:7), then by means of violence (animal pelts) (3:21). The punishments of God refer to the burden of foreseeing problems before they develop, symbolized by the "curse of the ground" or the hard work of agricultural, and the pain of giving birth to children with a large braincase (Genesis 3:16-19).
However, if tree of the knowledge of good and evil is to be understood to mean a tree whose fruit imparts knowledge of everything, this phrase does not necessarily denote a moral concept. This view is held by several scholars.
Given the context of disobedience to God, other interpretations of the implications of this phrase also demand consideration. Robert Alter emphasizes the point that when God forbids the man to eat from that particular tree, he says that if he does so, he is "doomed to die." The Hebrew behind this is in a form regularly used in the Hebrew Bible for issuing death sentences.
In Jewish tradition, the Tree of Knowledge and the eating of its fruit represents the beginning of the mixture of good and evil together. Before that time, the two were separate, and evil had only a nebulous existence in potential. While free choice did exist before eating the fruit, evil existed as an entity separate from the human psyche, and it was not in human nature to desire it. Eating and internalizing the forbidden fruit changed this and thus was born the yeitzer hara, the Evil Inclination. In Rashi's notes on Genesis 3:3, the first sin came about because Eve added an additional clause to the Divine command: Neither shall you touch it. By saying this, Eve added to YHWH's command and thereby came to detract from it, as it is written: Do not add to His Words (Proverbs 30:6). However, In Legends of the Jews, it was Adam who had devoutly forbidden Eve to touch the tree even though God had only mentioned the eating of the fruit.
When Adam ate from the Tree of Knowledge, all the animals ate from it, too 
In Kabbalah, the sin of the Tree of Knowledge (called Cheit Eitz HaDa'at) brought about the great task of beirurim, sifting through the mixture of good and evil in the world to extract and liberate the sparks of holiness trapped therein. Since evil has no independent existence, it depends on holiness to draw down the Divine life-force, on whose "leftovers" it then feeds and derives existence. Once evil is separated from holiness through beirurim, its source of life is cut off, causing the evil to disappear. This is accomplished through observance of the 613 commandments in the Torah, which deal primarily with physical objects wherein good and evil are mixed together. Thus, the task of beirurim rectifies the sin of the Tree and draws the Shechinah back down to earth, where the sin of the Tree had caused Her to depart.
In Catholicism, Augustine of Hippo taught that the tree should be understood both symbolically and as a real tree - similarly to Jerusalem being both a real city and a figure of Heavenly Jerusalem. Augustine underlined that the fruits of that tree were not evil by themselves, because everything that God created was good (Gen 1:12). It was disobedience of Adam and Eve, who had been told by God not to eat of the tree (Gen 2:17), that caused disorder in the creation, thus humanity inherited sin and guilt from Adam and Eve's sin.
In Western Christian art, the fruit of the tree is commonly depicted as the apple, which originated in central Asia. This depiction may have originated as a Latin pun: by eating the m?lum (apple), Eve contracted malum (evil). It is also possible that this depiction originated simply because of the religious painters' artistic licence.
The Quran never refers to the tree as the "Tree of the knowledge of good and evil" but rather typically refers to it as "the tree" or (in the words of Iblis) as the "tree of immortality." Muslims believe that when God created Adam and Eve, he told them that they could enjoy everything in the Garden except this tree, and so, Satan appeared to them and told them that the only reason God forbade them to eat from that tree is that they would become Angels or become immortals.
When they ate from this tree their nakedness appeared to them and they began to sew together, for their covering, leaves from the Garden. The Quran mentions the sin as being a 'slip', and after this 'slip' they were sent to the destination they were intended to be on - Earth. Consequently, they repented to God and asked for his forgiveness and were forgiven. It was decided that those who obey God and follow his path shall be rewarded with everlasting life in Jannah, and those who disobey God and stray away from his path shall be punished in Jahannam.
God in Quran (Al-A'raf 27) states: "[O] Children of Adam! Let not Satan tempt you as he brought your parents out of the Garden, stripping them of their garments to show them their shameful parts. Surely he [Satan] sees you, he and his tribe, from where you see them not. We have made the Satans the friends of those who do not believe."
A cylinder seal, known as the Adam and Eve cylinder seal, from post-Akkadian periods in Mesopotamia (c. 23rd-22nd century BCE), has been linked to the Adam and Eve story. Assyriologist George Smith (1840-1876) describes the seal as having two facing figures (male and female) seated on each side of a tree, holding out their hands to the fruit, while between their backs is a serpent, giving evidence that the fall of man account was known in early times of Babylonia. The British Museum disputes this interpretation and holds that it is a common image from the period depicting a male deity being worshipped by a woman, with no reason to connect the scene with the Book of Genesis.
The Tamil poem "Tala Vilasam" recounts a legend of the tree that parallels the Biblical account. In it, the Creator Brahma finally allows the people access to the tree- which, in this case, is the palmyra palmtree Borassus flabellifer.
American ethnomycologist, ethnobotanist, and philosopher Terence McKenna proposed that the Forbidden Fruit was entheogenic, identifying it as the Psilocybe cubensis mushroom, consistent with his "Stoned Ape" model of human evolution.
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