The events in Israel at the end of last week pierced and seared the hearts of many diaspora Zionists. The alleged perpetrators came from radically opposed sectors of Israeli society - the knife-wielding assassin at Gay Pride hailed from a strictly-Orthodox background that rejects the state of Israel; the settler terrorists emerged from the national-religious movement that aspires to achieve Zionist sovereignty across the entire Holy Land.
What they had in common, however, was the depraved belief that they were acting in service of their faith. But what is Jewish about "Jewish" extremism?
While it has been said that the Gay Pride attacker was mentally ill, he was presumably motivated by biblical prohibitions against homosexuality and anti-LGBT sentiment within some segments of Charedi society.
Scholars of Halachah and strict Orthodoxy must explain the context of his activities further.
Clearer conclusions can be drawn on the murder of toddler Ali Saad Dawabsheh by a radical fringe of the settler movement known as the "Hilltop Youth".
The late scholar Charles S Liebman characterised Israeli ultra-nationalism as a combination of territorial maximalism, xenophobia and the aim of creating a halachic state.
The violent expression of this agenda is not new to the settler movement. Since the 1980s, groups including the Jewish Underground and circles surrounding prime minister Yitzhak Rabin's killer Yigal Amir have embraced terrorism.
In recent years, notable figures like Hebron spiritual leader Dov Lior and Rosh Yeshiva of Yizhar Yitzhak Ginsberg - I deny both the honorific of 'Rabbi' - have promulgated racism and incited violence against gentiles.
It is suspected that the perpetrators of the recent assault were inspired by 24-year-old Bnei Brak resident Moshe Orbach's religious manifesto The Kingdom of Evil, which advocated the acceleration of attacks against holy sites and Palestinian civilians.
There is nothing Jewish about killing innocents in cold blood. We must root out this evil in our midst.
Dr Hirschhorn is lecturer in Israel Studies at the Oxford Centre for Hebrew and Jewish Studies
