People don't realize the power of jealousy — and how it's still destroying us today.

Chazal tell us the second Beis Hamikdash was destroyed because of sinat chinam, baseless hatred — and that this outweighs even the three cardinal sins that destroyed the first Temple. But "baseless" hatred doesn't really exist. Nobody hates for no reason. In this shiur we trace the real engine underneath sinat chinam back to its root: kinah, jealousy.

We follow jealousy from the Nachash and Chava in Gan Eden, through Kayin and Hevel, the sale of Yosef, Korach's rebellion, and Shaul's pursuit of Dovid — all the way to the churban of Yerushalayim and Beitar. Along the way we look at what jealousy actually does to the person carrying it (the Rishonim call it a disease with no cure), why the Torah closes the Ten Commandments with Lo Sachmod, and why the months of Tamuz and Av are called "the months of the eyes."

We'll also bring in the science: the famous capuchin monkey fairness experiments, Festinger's social comparison theory, fMRI research on envy and schadenfreude, and studies on how social media