Schism (pronounced "sizz-em", from the Greek σχίσμα schisma, rent, division) is the severing of ecclesiastical union and unity, either the act (a schism) by which one of the faithful (a schismatic) severs the ties of loyalty which bind him or her to the social organization of the Church and makes him or her a nominal member of the mystical body of Christ, or the state of dissociation or separation (being in schism) which is the result of that act, as in either (a) a passively negligent, or (b) a plainly stubborn, refusal to participate with the community in public worship (Hebrews 10:24-25). They have either stopped practicing the faith, or they have formed their own particular group of separate activists, by following others, in resisting the established leaders of the community who disagree with them, whom they prefer instead. St. Paul characterizes and condemns the schismatic parties formed in the community of Corinth: "I beseech you, brethren ... that there be no schisms among you; but that you be perfect in the same mind, and in the same judgment" (1 Corinthians 1:10-12) "that there might be no schism in the body" (1 Corinthians 12:25).
Schism of itself does not automatically imply heresy, just as heresy is not automatically the same as apostasy. The two terms are not synonymous. St. Jerome says, "Between heresy and schism there is this difference, that heresy perverts dogma, while schism, by rebellion against the bishop, separates from the Church. Nevertheless there is no schism which does not trump up a heresy to justify its departure from the Church (In The Letter to Titus, 3:10). And St. Augustine says, "By false doctrines concerning God heretics wound faith, by iniquitous dissensions schismatics deviate from fraternal charity, although they believe what we believe" (On Faith and the Creed 9). Catholicism maintains that schism leads almost invariably to denial of the papal primacy, as principally exemplified in the Great Schism of 1054 between Constantinople and Rome, and the founding of the Society of St. Pius X by the dissenting schismatic archbishop Marcel Lefebrve.
The principle perversity of most schisms is usually mixed schism, chiefly due to the heresy which forms part of it and by the divisiveness of its doctrine or doctrines tends to result in schism due to the stubbornness of the heretic. But simple pure schism, without any admixture of heresy, is strictly contrary to charity and obedience, because it severs the ties of fraternal charity, and because the schismatic rebels against the Divinely constituted hierarchy. Ecclesiastical disobedience to an authorized superior is not of itself a schism and does not of itself make one a schismatic. Besides direct transgression of the commands of superiors, actual schism must include explicit denial of their Divine right to command, refusal to acknowledge their authority (Numbers 16; Jude 8-11; Romans 13:1-2; Hebrews 13:17; Matthew 18:17-18; Titus 3:10-11; 1 John 2:18-19).