By 1 BC, the Yetzer Hatov concept was well established in Hebrew thought, especially in the Second Temple Period. It was rooted in the Tanakh (Old Testament) and early Jewish writings rather than later Greek philosophical interpretations.
Biblical Roots: While the term itself is not directly found in the Old Testament, the concept appears in verses like:
Genesis 6:5 – "The inclination (Yetzer) of the heart of man was only evil continually."
Deuteronomy 6:5 – "Love the Lord your God with all your heart..." (interpreted as following Yetzer Hatov).
Ecclesiastes 7:29 – "God made mankind upright, but they have sought many schemes."
Jewish Understanding
In early Hebrew thought, Yetzer Hara was not "demonic" or "Satanic." It was a human struggle between good and bad choices.
The Torah (Law) was given to help control the Yetzer Hara.
Yetzer Hara was necessary for survival (e.g., ambition, work, marriage, reproduction), but it had to be balanced by Yetzer Hatov (the good inclination).
Later Development (After 1 BC)
Greek influence (from Hellenism) introduced ideas of dualism—the battle between "good" and "evil" forces.
By the time of the Talmud (post-1st century AD), Yetzer Hara was described more like an "internal adversary."
Some later Jewish teachings connected it to an external tempter, but this was not the original Hebrew Bible view.
In the Old Hebrew Bible (pre-1 BC, without Greek influence), Yetzer Hara was the natural human tendency toward selfishness and temptation—not a fallen angel, demon, or external evil force. The Torah was given to guide people in mastering it through obedience and discipline.