Yetzer hara

In Judaism, yetzer hara (Hebrew: יֵצֶר הַרַע‎, romanized: yēṣer haraʿ‍) is a term for humankind's congenital inclination to do evil. The term is drawn from the phrase "the inclination of the heart of man is evil" (Biblical Hebrew: יֵצֶר לֵב הָאָדָם רַע, romanized: yetzer lev-ha-adam ra), which occurs twice at the beginning of the Torah (Genesis 6:5 and Genesis 8:21).

The Hebrew word yetzer having appeared twice in Genesis occurs again at the end of the Torah: "I knew their devisings that they do".^[1] Thus from beginning to end the heart's yetzer (plan) is continually bent on evil. However, the Torah which began with blessing^[2] anticipates future blessing^[3] which will come as a result of God circumcising the heart in the latter days.^[4]

In traditional Judaism, yetzer hara is not a demonic force, but rather man's misuse of things the physical body needs to survive. Thus, the need for food becomes gluttony due to the yetzer hara. The need for procreation becomes promiscuity, and so on.

The Jewish concept of the yetzer hara is similar to the Christian concept of a "sin nature" known as concupiscence, which is the tendency of humans to sin. However, concupiscence stems explicitly from original sin, while the yetzer hara is a natural part of God's creation.

According to the Talmudic tractate Avot de-Rabbi Natan, a boy's evil inclination is greater than his good inclination until he turns 13 (bar mitzvah), at which point the good inclination is "born" and able to control his behavior.^[5] Moreover, the rabbis have stated: "The greater the man, the greater his [evil] inclination."^[6]