The Age of Reason and the Age of Discretion

For most of Catholic history first communion was not a separate milestone at all: infants were confirmed and communed close to baptism in the ancient order of initiation still kept in the Christian East, and where medieval Western practice delayed communion it did so without ceremony, simply admitting children once a confessor judged them able to distinguish the Eucharist from ordinary bread.

Pope Pius X's 1910 decree Quam Singulari changed this by name, lowering the customary age of first communion to what it called the age of discretion, understood as roughly seven, against a nineteenth century pastoral drift toward delaying the sacrament until adolescence, and by doing so created the modern expectation of a distinct, celebrated occasion for young children rather than a quiet admission at whatever age a family or confessor judged fit. Around that decree grew the familiar Western Catholic custom: a class of children prepared together over one or more years of catechesis, dressed for the day in white, girls commonly in a small veil recalling bridal dress, and received as a group at a special parish Mass, often the first time the whole class has been the visible centre of the congregation's attention. Eastern Catholic and Orthodox practice, by contrast, never separated first communion from infant initiation and has no equivalent ceremony to mark.