Rabbi Eliezer recommended coitus interruptus for a duration of 24 months after birth. Tosafot cites the opinion of Rabbi Yitzchak (Isaac ben Samuel) who permitted an occasional exterior ejaculation with one's wife on the condition that one does not accustom himself to always doing so, as this is not considered comparable to Onan, who wished to avoid impregnating Tamar entirely. This opinion is accepted as normative by Rabbeinu Asher, Arba'ah Turim, Sefer HaAguddah, Maharsha, Bayit Chadash, Eliyah Rabbah, and some other authorities. A more explicit permissive stance is that of the tosafist rabbi Isaiah di Trani the Elder: Rabbi Isaiah the Elder's view is likewise echoed by his descendant, rabbi Isaiah di Trani the Younger. Rabbi Eleazar of Worms permits any activity with one's wife necessary to "quiet (lit. seat)" his desire. Non-Orthodox movements Reform and Reconstructionist rabbis have decided on more liberal conclusions. Reconstructionist Rabbi Alexis Roberts maintains that masturbation is "harmless, natural and healthy. It may provide release and pleasure, as well as self-knowledge that is useful for pleasurable sex with a partner. It may make it easier for young people to have sexual release in the years when they are too young for a mature, committed, loving relationship." Reform Rabbi Jonathan Stein, in a proposed schema for normative Reform evaluation of different sexual activities, proposed that masturbation be considered "mutar", a term generally translated as "permissible", but which he renders as "tolerable". Rabbi Walter Jacob, writing on behalf of the Reform responsa committee, asserts, "Although the statements of tradition are very clear, we would take a different view of masturbation, in the light of current psychological thought. Masturbation should be discouraged, but we would not consider it harmful or sinful." See also Religious views on masturbation Portnoy's Complaint Sacred Sperm Sexuality in Judaism References Masturbation Masturbation Religious views on masturbation