What’s the difference between excommunication and anathema?
God bless,
Father Hardon’s Modern Catholic Dictionary:
ANATHEMA. Solemn condemnation, of biblical origin, used by the Church to declare that some position or teaching contradicts Catholic faith and doctrine.
“If anyone,” Paul wrote to the Galatians, “preach to you a gospel besides what you have received, let him be anathema” (Galatians 1:9). Reflecting the Church’s concern to preserve the integrity of faith, the Fathers anathematized heretics in a variety of terms. Polycarp called Marcion the firstborn of the devil. Ignatius saw in heretics poisonous plants, or animals in human form. Justin (c. 100-65) and Tertullian (160-220) called their teachings an inspiration of the Evil One. Theophilus compared them to barren and rocky islands on which ships were wrecked, and Origen said they were pirates placing lights on cliffs to lure and destroy vessels in search of refuge. These primitive views were later tempered in language, but the implicit attitudes remained and were crystallized in solemn conciliar decrees. The familiar anathema sit (let him be anathema, or excommunicated) appears to have been first applied to heretics at the Council of Elvira (Spain) in 300-6, and became the standard formula in all the general councils of the Church, as against Arius (256-336) at I Nicaea (325), Nestorius at Ephesus (431), Eutyches at Chalcedon (451) and the Iconoclasts at II Nicaea in 787. (Etym. Greek anathema, thing devoted to evil, curse; and accursed thing or person; from anatithenai, to set up, dedicate.)
EXCOMMUNICATION. An ecclesiastical censure by which one is more or less excluded from communion with the faithful. It is also called anathema, especially if it is inflicted with formal solemnities on persons notoriously obstinate to reconciliation. Two basic forms of excommunication are legislated by the Code of Canon Law, namely inflicted penalties (ferendae sententiae) and automatic penalties (latae sententiae). In the first type, a penalty does not bind until after it has been imposed on the guilty party. In the second type, the excommunication is incurred by the very commission of the offense, if the law or precept expressly determines this (Canon 1314). Most excommunications are of the second type. Among others identified by the new Code are the following:
“An apostate from the faith, a heretic or a schismatic incurs automatic excommunication” (Canon 1364).
“A person who throws away the consecrated species or takes them or retains them for a sacrilegious purpose incurs an automatic excommunication reserved to the Apostolic See” (Canon 1367).
“A confessor who directly violates the seal of confession incurs an automatic excommunication reserved to the Apostolic See” (Canon 1388).
“A person who procures a successful abortion incurs an automatic excommunication” (Canon 1398).
There are three principal effects of this penalty, so that "an excommunicated person is forbidden:
to have any ministerial participation in celebrating the Eucharistic Sacrifice or in any other ceremonies whatsoever of public worship
to celebrate the sacraments and sacramentals and to receive the sacraments
to discharge any ecclesiastical offices, ministries or functions whatsoever, or to place acts of governance"
(Canon 1331).