Circumcision
Circumcision is very important to most branches of Judaism, with over 90% of male adherents having the procedure performed as a religious obligation. The basis for its observance is found in the Torah of the Hebrew Bible, in Genesis chapter 17, in which a covenant of circumcision is made with Abraham and his descendants. Jewish circumcision is part of the "brit milah" ritual, to be performed by a specialist ritual circumciser, a "mohel", on the eighth day of a newborn son's life, with certain exceptions for poor health. Jewish law requires that the circumcision leaves the glans bare when the penis is flaccid. Converts to Conservative and Orthodox Judaism must also be circumcised; those who are already circumcised undergo a symbolic circumcision ritual. Circumcision is not required by Judaism for one to be considered Jewish, but some adherents foresee serious negative spiritual consequences if it is neglected.
Religious male circumcision
During the nineteenth and twentieth centuries many Jewish reformers, doctors, and physicians in Central and Eastern Europe proposed to replace circumcision with a symbolic ceremony, while others sought to ban or abolish circumcision entirely, as it was perceived as a dangerous, barbaric and pagan ritual of genital mutilation that could transmit infectious diseases to newborns. The first formal objection to circumcision within Judaism occurred in 1843 in Frankfurt. The Society for the Friends of Reform, a group that criticized traditional Jewish practices, said that brit milah was not a mitzvah but an outworn legacy from Israel's earlier phases, an obsolete throwback to primitive religion. With the expanding role of medicine came further opposition; certain aspects of Jewish circumcision such as "periah" and "metzitzah" (drawing the blood from the circumcision wound through sucking or a cloth) were deemed unhygienic and dangerous for the newborns. Later evidence that syphilis and tuberculosis – two of the most feared infectious diseases in the 19th century – were spread by mohels, caused various rabbis to advocate "metzitzah" to be done using a sponge or a tube. Among the secular, non-observant Jews that chose to not circumcise their sons and keep them intact there was also Theodor Herzl.
A growing number of contemporary Jews and Intactivist Jewish groups in the United States, United Kingdom, and Israel, both secular and religious, started to question overall long-term effects, psychological and psychophysical consequences of trauma caused by circumcision on Jewish children, and choose not to circumcise their sons. They are assisted by a small number of Reform, Liberal, and Reconstructionist rabbis, and have developed a welcoming ceremony that they call the "Brit shalom" ("Covenant [of] Peace") for such children, also accepted by Humanistic Judaism.