Individual prayer is considered acceptable, but prayer with a quorum of ten Jewish adults—a "minyan"—is the most highly recommended form of prayer and is required for some prayers. An adult in this context means over the age of 12 or 13 ("bat" or "bar mitzvah"). Judaism had originally counted only men in the "minyan" for formal prayer, on the basis that one does not count someone who is not obligated to participate. The rabbis had exempted women from almost all time-specific positive mitzvot (commandments), including those parts of the prayer that cannot be recited without a quorum, due to women in the past being bound up in an endless cycle of pregnancy, birthing and nursing from a very early age. Orthodox Judaism still follows this reasoning and excludes women from the minyan.