By Father Michael Azkoul
St. Catherine Mission, St. Louis, MOThis question has been asked many times. Most Orthodox, in attempting to distinguish between Orthodoxy and Roman Catholicism, usually mention the Pope or Purgatory, sometimes the filioque. Historically, the differences, however, are far more numerous and quite profound.
Also, in modern times, since Vatican II of thirty years ago, that major, if not tragic attempt, to "update" Roman Catholicism (e.g., the revision of canon law), the differences between Orthodoxy and the followers of the Pope have widened.
In our present discussion, however, the concern will be those differences which have grown since Orthodoxy and Roman Catholicism separated almost a thousand years ago.
1. Faith and Reason
Following the Holy Fathers, Orthodoxy uses science and philosophy to defend and explain her Faith. Unlike Roman Catholicism, she does not build on the results of philosophy and science. The Church does not seek to reconcile faith and reason. She makes no effort to prove by logic or science what Christ gave His followers to believe. If physics or biology or chemistry or philosophy lends support to the teachings of the Church, she does not refuse them. However, Orthodoxy is not intimidated by man's intellectual accomplishments. She does not bow to them and change the Christian Faith to make it consistent with the results of human thought and science.
St. Basil the Great advised young monks to use Greek philosophy as a bee uses the flower. Take only the "honey," ---- the truth --- which God has planted in the world to prepare men for the Coming of the Lord.
For example, the Greeks had a doctrine of the Logos. The Gospel of John opens, "In the beginning was the Word (Logos, in Greek). For the pagans, the Logos was not God, as He is for Christians; rather he is a principle, a power or force by which "God: formed and governs the world. The Fathers pointed to the similarity between the Logos or Word of the Bible and the Logos of Greek philosophy as a sign of Providence. The difference between them, they attributed to the sinfulness of men and the weakness of the human intellect. They remembered the words of the Apostle Paul, "Beware lest any man spoil you through philosophy and vain deceit, after the tradition of men, after the rudiments of the world, and not after Christ" (Col. 2: 8).
Roman Catholicism, on the other hand, places a high value on human reason. Its history shows the consequence of that trust. For example, in the Latin Middle Ages, the 13th century, the theologian-philosopher, Thomas Aquinas, joined "Christianity" with the philosophy of Aristotle. From that period til now, the Latins have never wavered in their respect for human wisdom; and it has radically altered the theology, mysteries and institutions of the Christian religion.
2. The Development of Doctrine
The Orthodox Church does not endorse the view that the teachings of Christ have changed from time to time; rather that Christianity has remained unaltered from the moment that the Lord delivered the Faith to the Apostles (Matt. 28: 18-20). She affirms that "the faith once delivered to the saints" (Jude 3) is now what it was in the beginning. Orthodox of the twentieth century believe precisely what was believed by Orthodox of the first, the fifth, the tenth, the fifteenth centuries.
To be sure, Orthodoxy recognizes external changes (e.g., vestments of clergy, monastic habits, new feasts, canons of ecumenical and regional councils, etc.), but nothing has been added or subtracted from her Faith. The external changes have a single purpose: To express that Faith under new circumstances. For example, the Bible and divine Services were translated from Hebrew and Greek into the language of new lands; or new religious customs arose to express the ethnic sensibilities of the converted peoples, etc.; nevertheless, their has always been "one faith, one Lord, one baptism" (Eph. 4: 4).
The fundamental witness to the Christian Tradition is the holy Scriptures; and the supreme expositors of the Scriptures are the divinely inspired Fathers of the Church, whether the Greek Fathers or Latin Fathers, Syriac Fathers or Slavic Fathers. Their place in the Orthodox religion cannot be challenged. Their authority cannot be superseded, altered or ignored.
On the other hand, Roman Catholicism, unable to show a continuity of faith and in order to justify new doctrine, erected in the last century, a theory of "doctrinal development."
Following the philosophical spirit of the time (and the lead of Cardinal Henry Newman), Roman Catholic theologians began to define and teach the idea that Christ only gave us an "original deposit" of faith, a "seed," which grew and matured through the centuries. The Holy Spirit, they said, amplified the Christian Faith as the Church moved into new circumstances and acquired other needs.
Consequently, Roman Catholicism, pictures its theology as growing in stages, to higher and more clearly defined levels of knowledge. The teachings of the Fathers, as important as they are, belong to a stage or level below the theology of the Latin Middle Ages (Scholasticism), and that theology lower than the new ideas which have come after it, such as Vatican II.
All the stages are useful, all are resources; and the theologian may appeal to the Fathers, for example, but they may also be contradicted by something else, something higher or newer.
On this basis, theories such as the dogmas of "papal infallibility" and "the immaculate conception" of the Virgin Mary (about which we will say more) are justifiably presented to the Faithful as necessary to their salvation.
In any case, the truth of these dogmas have always belonged to the Christian Tradition. They have been present from the beginning of that Tradition as "hints," seeds that only waited for the right time to bloom.
3. God
Roman Catholicism teaches that human reason can prove that God is; and, even infer that He is eternal, infinite, good, bodiless, almighty, all-knowing, etc. He is "most real being," "true being." Humans are like Him (analogous), but we are imperfect being. The God of Roman Catholicism, born in the Latin Middle Ages, is not " the God of Abraham, Isaac and Jacob, but the God of the savants and the philosohers," to adapt the celebratted phrase of Blaise Pascal.
Following the Holy Fathers, Orthodoxy teaches that the knowledge of God is planted in human nature and that is how we know Him to exist. Otherwise, unless God speaks to us, human reason cannot know more. The saving knowledge of God comes by the Savior. Speaking to His Father, He said, "And this is life eternal, that they might know Thee, the only true God, and Jesus Christ, Whom Thou has sent" (John 17: 3).
Roman Catholicism teaches, also, that, in the Age to Come, man will, with his intellect and with the assistance of grace, behold the Essence of God. The Fathers declare that it is impossible to behold God in Himself. Not even divine grace, will give us such power. The saved will see, however, God as the glorified flesh of Christ.
Historically, the Roman Catholic theology never made the distinction between God's Essence (what He is) and His Uncreated Energies (by what means He acts). St. Gregory Palamas tried to explain this distinction through a comparison between God and the Sun. The sun has its rays, God has His Energies (among them, Grace and Light). By His Energies, God created, sustains and governs the universe. By His Energies, He will transform the creation and deify it, that is, He will fill the new creation with His Energies as water fills a sponge.
Finally, Roman Catholicism teaches that the Holy Spirit "proceeds from the Father and the Son" (filioque). In so doing, it spurned the Apostolic Tradition which always taught that God the Father is the single Source ("monarchy") of the Son and the Spirit. Thus, the Latins added words to the Nicean Creed
"I believe in the Holy Spirit, the Lord, the Giver of Life, Who proceeds from the Father and the Son . . .
They made this change on the authority of the Pope, in the 11th century, not any Council of the whole Church (Ecumenical Council).
4. Christ
Why did God become man? The Roman Catholic answer to this question differs from the teachings of the Holy Orthodox Church.
Following the holy Fathers, Orthodoxy teaches that Christ, on the Cross, gave "His life a ransom for many" (Matt. 20:28). "For even the Son of man came not to be served, but to serve, and to give His life a ransom for many" (Mark 10:45). The "ransom" is paid to the grave. As the Lord revealed to the Prophet Hosea (Hosea 13:14), "I will ransom them (us) from the power of the grave, I will redeem them from death." In a sense, He pays the ransom to the devil who has the keeper of the grave and holds the power of death (Heb. 2:14).
The man Christ voluntarily gave Himself on the Cross. He died for all ("a ransom for many" or "the many"). But He rose from the dead in His crucified body. Death had no power to hold Him. It has no power over anyone. The human race is redeemed from the grave, from the devil. Free of the devil is to be free of death and sin. To be free of these, we become like God (deification) and may live with Him forever.
According to Roman Catholic theology, God became man in order to satisfy the divine Justice which was offended by the sin of Adam. In other words, by his sin Adam offended the infinite God and, therefore, his sin had infinite consequences. It was not within the power of sinful and finite man to make amends, for the sin of Adam ("original sin") passed to us; but it is our obligation to do so. Only Christ, Who was God and man, could pay this "debt of honor."
He pays the debt by dying on the Cross. His death makes up for what Adam had done; the offense is removed. God is no longer angry with man. Christ rises from the dead, the promise or "earnest" of the believing man's future. For a long time, the Latins, whether among ordinary Catholics or intellectuals, little attention was given to the idea of deification. Not much attention was devoted to the concepts necessary to understanding this doctrine.
Roman Catholic theology is customarily legalistic and philosophical. For example, a "valid" (legal term) baptism into Christ is the result of the right intention (having the same understanding of baptism as the Church) and using the correct formula or words during the ceremony or rite. Thus, even an atheist, under certain conditions, could baptize a person. "Sprinkling" of water (effusion) over the head of the baptized is reasonable and sufficient.
Lately, some Latin theologians are rethinking the Christian teaching of salvation (soteriology). They are beginning to take the idea of deification (baptism as the first step) very seriously. They rightly insist that it belongs to Christian tradition, including "St. Augustine" and other Latin Fathers. In point of fact, a revolution in its theology is necessary if it is to become Scriptural and patristic; if it ever hopes to achieve the right understanding of Christ and His salvation.
5. The Church
The Roman Catholic view of the Church (ecclesiology) differs from the Orthodox teaching on this subject in several ways.
The Latins teach that the visible head of the Church is the Pope, the successor to St. Peter, who was appointed to that sacred position by the Lord Himself with the words, "Thou art Peter and upon this rock I shall build my Church . . . " (Matt. 16:18).
The Pope is, then, "the Bishop of the Catholic Church," her teacher, the vicar (agent, deputy) of Christ on earth. He is the interpreter of the Christian Tradition. When he speaks for the whole Church (ex cathedra), the Holy Spirit does not permit him to err. He is, therefore, infallible on matters of morals and doctrine. Other bishops are his lieutenants. He is the symbol of the episcopate's unity.
The Orthodox Church teaches that all bishops are equal. To be sure, there are different ranks of bishops (patriarch, archbishop, metropolitan, bishop); nevertheless, a bishop is a bishop. Such differences apply to the administration of a church or group of churches, not to the nature of the bishop. The president of a synod of bishops is called archbishop (Greek custom) or metropolitan (Russian custom).
According to Latin ecclesiology, each local parish is part of the universal or whole Church. The totality of Catholic parishes form the Body of Christ on earth. This visible Body has a visible head, the Pope. This idea of the Church implies that the local parish has two heads: the Pope and the local bishop. But a body with two visible heads is a monster. Also, the local bishop seems stripped of his apostolic authority if the Pope may contradict his orders. Indeed, he cannot become a bishop unless the Pope allows it.
Orthodoxy teaches that every bishop, "the living icon of Christ," and his flock constitute the Church in a certain place; or, as St. Ignatius the God-bearer says, the Church of Christ is in the bishop, his priests and deacons, with the people, surrounding the Eucharist in the true faith. All bishops and their flocks so constituted, together composing the One, Holy, Catholic and Apostolic Church.
In other words, there can be no Church without a bishop, no bishop without the Eucharist, and no bishop or Eucharist without the true faith, the Apostolic Faith, "the faith once delivered to the saints." (Jude 3) "The Church is in the bishop and the bishop in the Church," wrote St. Cyprian of Carthage.
Put another way, there is no Church where there is no bishop, and there is no bishop where there is no succession of bishops from the Apostles (apostolic succession); and there can be no succession from the bishops without the faith of the Apostles.
Also, there can be no Church without the Eucharist, the Sacrament of unity, because the Church is formed through it. The Body and Blood of Christ unites the Faithful to God: This fellowship or koinonia is the whole purpose of Christianity. At the same time, there can be no Eucharist - and no other Mysteries - without a bishop who teaches the true faith to the baptized.
6. The Holy Canons
A canon is a "rule" or "guide" for governing The Church. Canons were composed by the Apostles, the Fathers, the local or regional and general or ecumenical Councils (in Latin) or Synods (in Greek). Only the bishop, as head of the church, applies them. He may use them "strictly" (akreveia) or "leniently" (economia). "Strictness" is the norm.
Unlike the Latins, the Orthodox Church does not think of canons as laws, that is, as regulating human relationships or securing human rights; rather, Orthodoxy views canons as the means of forging the "new man" or "new creature" through obedience. They are training in virtue. They are meant to produce holiness.
The Latins continue to change their canons, ignoring the old for the new. Not more than two decades ago, Rome revised its Canon Law. It composes new canons to keep up with the times. On the other hand, Orthodoxy, albeit adding canons from time to time and place to place, never discards the old ones, for they, too, are inspired by the Holy Spirit. In any case, human problems and spiritual needs do not really change. New canons are generally simple refinements of old canons.
7. The Mysteries
Both the Orthodox and the Roman Catholics recognize at least seven Sacraments or Mysteries: The Eucharist, Baptism, Chrismation, Ordination, Penance, Marriage and Holy Oil for the sick (which the Latins have traditionally called "Extreme Unction" and reserved for the dying).
Concerning the Sacraments in general, the Orthodox teach that their material elements (bread, wine, water, chrism, etc.) become grace-filled by the calling of the Holy Spirit (epiklesis). Roman Catholicism believes that the Sacraments are effective on account of the priest who acts "in the person of Christ."
At the same time, the Latins interpret the Sacraments in a legal and philosophical way. Hence, in the Eucharist, using the right material things (bread and wine) and pronouncing the correct formula, changes their substance (transubstantiation) into the Body and Blood of Christ. The visible elements or this and all Sacraments are merely "signs" of the presence of God.
The Orthodox call the Eucharist "the mystical Supper." What the priest and the faithful consume is mysteriously the Body and Blood of Christ. We receive Him under the forms of bread and wine, because it would be wholly repugnant to eat "real" human flesh and drink "real" human blood.
According to Roman Catholic teachings about the Sacraments (mystagogy), a person becomes a member of the Church through Baptism. "Original sin" is washed away. Orthodoxy teaches the same, but the idea of an "original sin" or "inherited guilt" (from Adam) has no part in her thinking. More will be said later on this matter.
Roman Catholics speak of "Confirmation" and the Orthodox of "Chrismation." "Confirmation" is separated from the Baptism and is performed by the bishop and not the priest; but "Chrismation" is performed with Baptism by a priest who has received "chrism" from the bishop. The Sacrament of "Confirmation" and "Chrismation" both mean the giving of the Holy Spirit. The Latins delay "confirming" (with "first communion") baptized infants not more than seven years, that is, until the time they have some appreciation of the gift of God.
The Orthodox Church links Baptism, Chrismation and Holy Communion, first the threefold immersion into sanctified water, the "new Christian" rising from the water into the fellowship of the Holy Spirit which leads to union with God. Such is the purpose of membership in the Church.
Ordination is the ceremony which, by the grace and calling of God, elevates a man to the priesthood. The sacerdotal priesthood has three orders: Bishop, presbyter (elder) and deacon. All Christians are priests by virtue of the baptism into Christ Who is priest, prophet and king - for which reason St. Peter refers to the Church as a "royal priesthood" (I Pet. 2:9). The bishop is the "high priest," the "president of the Eucharist and all the Mysteries. Presbyters and deacons are his assistants. The Latins hold that the presbyter acts "in the person of Christ" when, in fact, he does no more than represent the bishop who is "the living icon of Christ."
Strictly speaking, Penance - sometimes called "Confession" - should only be received by the believer as a means of re-admission to the Church. For a long time, Penance, or confession of sins, prayer and fasting was employed only for those who had been expelled from the Church ("excommunication") or who had voluntarily departed (apostasy). The present practice is to receive Penance from a bishop or presbyter for some serious sin before receiving Holy Communion.
Both the Orthodox and the Roman Catholics consider Penance as a Sacrament. Each has different customs surrounding it, such as the confessional booth so common among the latter.
For Roman Catholics, Holy Matrimony is a binding, ostensibly an unbreakable, contract. The man and the woman marry each other with the "church" (bishop or priest) standing as a witness to it. Hence, no divorce under any conditions - no divorce but annulment of the marriage contract if some canonical defect in it may be found which renders it null and void (as if it never took place).
In Orthodoxy, Holy Matrimony is not a contract; it is the mysterious or mystical union of a man and woman - in imitation of Christ and the Church - in the presence of "the whole People of God" through her bishop or his presbyter. Divorce is likewise forbidden, but, as a concession to human weakness, it is allowed for adultery. Second and third marriages are permitted - not as a legal matter - out of mercy, a further concession to human weakness (e.g., after the death of a spouse). This Sacrament, as all Sacraments or Mysteries, is completed by the Eucharist, as St. Dionysius the Areopagite says.
As already mentioned, the Latins conceive Extreme Unction as the final Sacrament, the Sacrament which prepares the believer for death, purgatory and the Age to Come. In Orthodoxy, Holy Oil is received for healing. Often sickness is caused by sin; therefore, Holy Oil or Unction involved Confession of sins. At the end of the rite, the anointed receives Holy Communion.
The Orthodox Church also recognizes kingship, monasticism, blessings of the water, etc. as Mysteries.
8. The Nature of Man
Human nature was created good, even in communion with the blessed Trinity which made "him." Male and female were created "in the likeness and image of God" (Gen. 1:26): "likeness" in virtue; "image" meaning to rule the earth rationally, to act wisely and freely. The woman was made as a "help-meet" to the man (Gen. 2:18; I Cor. 11:8-9). They were to live together in harmony and mutual respect.
So far Roman Catholicism agrees with the Church; it differs with Orthodoxy on the nature of man's fall and the human condition. Following Augustine of Hippo, the Latins teach that Adam and Eve sinned against God. The guilt of their sin has been inherited by every man, woman and child after them. All humanity is liable for their "original sin."
Following the Holy Fathers, the Orthodox Church holds that when Adam sinned against God, he introduced death to the world. Since all men are born of the same human stock as Adam, all men inherit death. Death means that the life of every human being comes to an end (mortality); but also that death generates in us the passions (anger, hate, lust, greed, etc.), disease and aging.
Roman Catholicism has ordinarily paid little attention to the Orthodox conception of man as slave to death through his passions as manipulated by the devil. In fact, the devil has been pushed to the background. Thus, the Crucifixion has been understood by the Latins as Christ suffering punishment for the human race ("vicarious atonement"), when, in truth, Christ suffered and died on the Cross to conquer the devil and destroy his power, death.
In any case, Orthodoxy has always put great stress on "mastery of the passions" through prayer (public worship and private devotions), fasting (self-denial) and voluntary obedience and regular participation in the Eucharist (sometimes called "the Mysteries"). Thus, the highest form of Christian living ("the supreme philosophy") is monasticism. Here all human energy is devoted to struggle for perfection.
Monasticism, in this sense, among Roman Catholics has all but disappeared. As a "supernatural religion" so-called, it has become increasingly "this-worldly." Therefore, it has abandoned its medieval heritage, and its understanding of man, his nature and destiny has become increasingly secular.
9. The Mother of God
The doctrine of the place and person of the Virgin Mary in the Church is called "mariology." Both Orthodoxy and Roman Catholicism believe she is "Mother of God" (Theotokos, Deipare) and "the Ever-Virgin Mary."
However, the Orthodox reject the Roman Catholic "dogma of the Immaculate Conception of the Virgin Mary," which was defined as "of the faith" by Pope Pius IX, on the 8th of December 1854. This dogma holds that from the first instant of her conception, the Blessed Virgin Mary was, by a most singular grace and privilege of Almighty God, and in view of the merits of Jesus Christ, the Redeemer of the human race, preserved from all stain of Original Sin. It is a doctrine revealed by God, and therefore to be firmly and steadfastly believed by all the faithful (from the Bull Ineffabilis Deus).
Such a theory has no basis in the Scriptures nor the Fathers. It contains many ideas (such as "the merits of Christ") likewise without apostolic foundation. The idea that the Lord and His Saints produced more grace than necessary. This excess may be applied to others, even those in purgatory (see below).
But to return: the Church does not accept the idea that the Mother of God was born with the (inherited) guilt of Adam; no one is. She did, however, inherit the mortality which comes to all on account of Adam's Fall.
Therefore, there is no need to do what Latin theologians have done. There is no reason to invent a theory to support the dogma of the Immaculate Conception. There is no need to teach that, on account of "the merits of Christ," the Holy Spirit was able to prevent her from inheriting the guilt of Adam.
In fact, she was born like every other human being. The Holy Spirit prepared the Virgin Mary for her role as the Mother of God. She was filled with the Uncreated Energy of the Holy Spirit of God in order that she might be a worthy vessel for the birth of Christ. Nevertheless, several of the Fathers observed that before the Resurrection of her Son, she had sinned. St. John Chrysostom mentions the Wedding at Cana where she presumed to instruct Him (John 2:3-4). Here was proof of her mortality.
Receiving the Holy Spirit once more at Pentecost, she was able to die without sin. Because of her special role in the Divine Plan ("economy" or "dispensation"), she was taken into the heavens, body and soul. She now sits at the foot of her Son, making intercession for all those who implore her mercy. The Orthodox Church honors the miracle of her "assumption" with a feast on 15 August; likewise, the followers of the Pope.
Both also believe in the intercessions of the Virgin Mary and all the Saints. Such intercessions reflect the unity of the Church in heaven and the Church on earth.
Both also believe that there is a sense in which the Mother of God is the Church. The Church is the Body of Christ. Those who belong to the Church are identified with Him. But He is also our "brother" (Rom. 8:29). If Christ is our brother, then, the Virgin Mary is our mother. But the Church is our mother through Baptism. Therefore, the Virgin Mary is the Church.
10. Icons
The icon is an artistic depiction of Christ, the Mother of God and the Saints. God the Father cannot be painted, because He has never been seen. God the Holy Spirit has appeared as a dove and as "tongues of fire." He may be shown in this way. God the Son became a man, and He may be painted in His human form.
Icons are more than sacred pictures. Everything about them is theological. For example, they are always flat, flat so that we who inhabit the physical world will understand that the world of the spirit where Christ, His Mother, the angels, the saints, and the departed dwell, is a world of mystery which cannot be penetrated by our five senses.
Customarily, Roman Catholicism has historically employed statues in its worship. The statues are life-like and three-dimensional. They seem to imitate the art of ancient Greece. Both arts are naturalistic. The Latins portray Christ, the Mother of God, the saints, even the angels, as if they were in a state of nature. This "naturalism" stems from the medieval idea that "grace perfects nature."
The person or persons are represented on the icon as deified. He or she is not a perfect human being, but much more: They are transfigured and glorified. They have a new and grace-filled humanity.
Important to remember is the Latin theory of grace: It is created by God for man. Orthodoxy teaches, as we recall, that grace is uncreated, and impacts all creation. It is a mysterious extension of the Divine Nature. Orthodox iconography reflects this truth, even as Roman Catholic statues reflect its idea of grace.
Again, icons are a necessary part of Orthodox piety. The Orthodox honor and kiss icons, a devotion which passes from the icon to the person or persons represented in them. Icons are not idols and the Orthodox do not worship them. Worship is reserved for God alone. The statues set up in Roman Catholic temples are not commonly venerated; they are visual aids and decorations.
11. Purgatory
Purgatory is a condition of the departed before the final judgment. According to Roman Catholic theology, those souls destined for heaven (with a few exceptions) must endure a state of purgation, or purification. They must be cleansed of the sins committed on earth. The rest go to hell for eternal punishment.
Moreover, from a "treasury" of merits or extra grace accumulated by the virtue of Christ, the Virgin Mary and the saints, "indulgences" may be granted. The grace is applied to those in purgatory in order to shorten their time there.
Orthodoxy teaches that, after the soul leaves the body, it journeys to the abode of the dead (Hades). There are exceptions, such as the Theotokos, who was borne by the angels directly into heaven. As for the rest, we must remain in this condition of waiting. Because some have a prevision of the glory to come and others foretaste their suffering, the state of waiting is called "Particular Judgment."
When Christ returns, the soul rejoins its risen body to be judged by Him. The "good and faithful servant" will inherit eternal life, the unfaithful with the unbeliever will spend eternity in hell. Their sins and their unbelief will torture them as fire.
12. Other Differences
There are other minor differences between the Orthodox Church and Roman Catholicism.
The Orthodox do not fast on Saturday (except Holy Saturday) or Sunday. Roman Catholics experience no such restriction.
Orthodox do not kneel on Sunday; Roman Catholics do. Orthodox have no "Stations of The Cross;" Roman Catholics do.
Orthodox presbyters and deacons may marry before ordination; Roman Catholic clergy are celibate.
Orthodox worship towards the East; Roman Catholics, not necessarily.
In the Orthodox Liturgy, the "bread" of the Eucharist is "leavened" (zyme); in the Roman Catholic Mass it is "unleavened" (azyme).
The Orthodox faithful receive both the "body" and "blood of Christ" in Holy Communion; Roman Catholics receive only the "bread," a wafer.
There are no orders of Orthodox monks (male and female) as there is among Roman Catholics (Jesuits, Dominicans, Benedictines, Cistericans, etc.). More recently, many Roman Catholic monks and nuns have put away their traditional habits.
Orthodox clergy wear beards; Papist clergy are generally beardless.
There are many other differences, often the product of culture. Also, it is noteworthy that many of these differences, whether profound or not, do not apply to the contemporary religious situation. Ecumenism has brought great confusion, so that it is not always easy to say with any precision what Roman Catholics believe, while so-called Orthodox have abandoned the traditional teachings of the Church.