ΙΧΘΥΣ = Ἰησοῦς Χριστός Θεοῦ Υἱὸς Σωτήρ (‘Jesus Christ, Son of God, Saviour’)
The sign of the fish, used by the early Church as a secret Christian insignia as well as a symbol representing Christ and the Eucharist in art and literature. This symbol may derive from an appellation for the disciples, “fishers of men” (Luke 5:10), or from Jesus’ miraculous feeding of the five thousand (Matt. 14:13–21 par.). The word is an acronym whose letters represent I(ēsous) Ch (ristos) Th (eou) Y (ios) S (ōtēr), meaning Jesus Christ, Son of God, Savior.
THE HISTORY OF CHRISTIAN FISH SYMBOL
The Fish was the most popular symbol of our Lord in the middle of the 2nd cent., and continued so till the end of the 4th, when it suddenly went out of use. More than one cause made it so general. Originating as an acrostic (the Greek word for ‘fish,’ ΙΧΘΥΣ, standing for Ἰησοῦς Χριστός, Θεοῦ Υἱός, Σωτήρ), it formed a most convenient secret sign among the Christians, being readily understood by the initiated as representing Christ in the fulness of His divinity.
It carried with it also the thought of the sacramental feeding upon the Son of God, which is so prominent in early Christian art: e.g. the two paintings in the crypt of Lucina, which belong to the middle of the 2nd cent., and represent two baskets of bread, each containing a glass cup of wine and resting upon a fish.
The earliest known representation of this symbol is even more significant: it occurs in the Fractio Panis fresco, recently discovered by Wilpert in the Catacomb of Priscilla, which belongs to the beginning of the 2nd cent., and is a picture of a primitive celebration of the Communion,—seven people are seated at a table on which lie live loaves, two fishes, and a two-handled mug, while the bishop or president at the end of the table is in the act of breaking a loaf.
In this deeply interesting picture of the Eucharist we see a further reason why the Fish symbol was felt to be appropriate; it carried the mind to the miracle of the loaves and fishes, which was an early type of the Eucharist because of Jn 6:9–59. The Fish symbolizes not only the Eucharist, but the sacrament of Baptism as well; this is brought out by the common representation of a fish as swimming in the water (see below under ‘Symbolic Scenes’). ‘We little fishes,’ says Tertullian (de Bapt. i.), ‘after the example of our Ichthus Jesus Christ, are born in water.’ Cf.St. Clement below, under ‘Other Symbols.’ This double symbolism is tersely expressed in the 2nd cent, inscription of Abercius recently discovered by Ramsay at Hierapolis:—‘… everywhere was faith my guide, and gave me everywhere for food the Ichthus from the spring.’
Percy Dearmer, “Christ in Art,” ed. James Hastings, A Dictionary of Christ and the Gospels: Aaron–Zion (Edinburgh; New York: T&T Clark; Charles Scribner’s Sons, 1906), 308–309.
FISH IN CHRISTIAN SYMBOLISM
Of all the symbols used by the early Christians, none was more widely used than that of the fish. It was employed as a metaphor in the writings of the fathers of the Church, and was graven or painted as a secret sign upon monuments of all kinds. We do not speak, of course, of the fish introduced into arabesque ornamentation, or into the scenes drawn from the New Testament, nor of those cases where it was used upon tombs to indicate the calling of the deceased, but of those cases where it was used independently, and manifestly in a purely symbolical sense. Numberless examples are extant of its being thus used on tombstones, rings, seals, and amulets. It manifestly had two significations, sometimes referring to Christ, and sometimes to the Christian Church.
I. Referring to Christ, it was in familiar use as early as the 2d century. Its significance was drawn from the fact that the letters of ἰχθύς, the Greek word for fish, form the initials of the acrostic Ἰησοῦς, Χριστός, Θεοῦ, Υἱός, Σωτήρ (Jesus Christ, Son of God, Saviour). The complete acrostic is found upon but one monument, a tombstone. It is explained in the writings of St. Augustine. Sometimes the entire word was used; in other cases there were but parts of it. The figure of a fish was very frequently cut or painted to represent the Saviour. Fishes of glass or of bronze were often hung upon the necks of believers as amulets. Seals and rings often had other symbols also, as the anchor, the cross, and the A Ω. The fish was especially used on baptismal fonts and on the walls of baptisteries. A ship resting on a fish was used to indicate that Christ supports the Church.
II. The fish represents the Christian in all artistic presentations of those parabļes where the apostles are spoken of as fishers of men. The fish, attached to a hook and line, with or without a fisherman, always refers to the Christian, as do those representations of a number of fishes on pavements of churches, and on those tombstones where funeral inscriptions, as in pace, are added. Often two fishes are given, one on each side of an anchor or a cross. Many interpretations are given of this, the best established being the one that considers them as referring to the Jews and Gentiles, though much weight is attached to the interpretation which considers the two fishes to allude to the two covenants, the Jewish and the Christian. The baptisteries were therefore sometimes called piscinæ. Tertullian speaks of Christians as accustomed to please themselves with the name pisciculi, “fishes,” to denote that they were born again into Christ’s religion by water. He says, Nos pisciculi secundum ἰχθύν, nostrum Jesum Christum, in aquâ nascimur (De Bapt. ch. i).
The use of the fish as a symbol ceased almost entirely with the death of Constantine the Great, though examples are found of it as late as the 5th or 6th century.—Rossi, De Christianis Monumentis ΙΧΘΥΝ exhibentibus V 3, p 579 (Par. 1855); Martigny, Dictionnaire des Antiquités Chrétiennes (Paris, 1865); Piper, Die christliche Kunst; Becker, Die Darstellung Jesu Christi unter dem Bilde des Fisches (Breslau, 1866, 8vo); Didron, Christian Iconography, i, 344; Bingham, Orig. Eccles. bk. i, ch. i, § 2. (G. F. C.)
G. F. Comfort, “Fish in Christian Symbolism,” Cyclopædia of Biblical, Theological, and Ecclesiastical Literature (New York: Harper & Brothers, Publishers, 1891), 578–579.