Ichthys or Ichthus Greek: ἰχθύς, capitalized ΙΧΘΥΣ; also transliterated and Latinized as ichthys, icthus, ichthus or ikhthus; ichthus), is the Ancient and Classical Greek word for "fish." In English it refers to a symbol consisting of two intersecting arcs, the ends of the right side extending beyond the meeting point so as to resemble the profile of a fish, said to have been used by early Christians as a secret symbol and now known colloquially as the "sign of the fish" or the "Jesus fish.
Historically, twentieth century use of the ichthys motif is an adaptation based on an Early Christian symbol which included a small cross for the eye or the Greek letters "ΙΧΘΥΣ". Catholic theology has elaborated on the five words of the acronym into the "Jesus prayer", or, "Lord Jesus Christ, Son of God, have mercy on me, a sinner."
An ancient adaptation of ichthus is a wheel which contains the letters ΙΧΘΥΣ superimposed such that the result resembles an eight-spoked wheel.
Within astrology, the symbol of the fish can also have the double meaning of the sign of Pisces. According to some astrological theorists, Jesus Christ represents the central figure of the Age of Pisces, which is now giving way to the Age of Aquarius. The Ages go backwards through the signs of the Zodiac. Prior to the birth of Christ there was the Age of Aries and before that Taurus and so on. Each Age lasts approximately 2,000 years.
At the feeding of the five thousand, a boy is brought to Jesus with "five small loaves and two fishes". The question is asked, "But what are they, among so many?" Jesus multiplies the loaves and fish to feed the multitude.
In , Jesus compares God's decision on who will go to heaven or to hell ("the fiery furnace") at the end of this world to fishers sorting out their catch, keeping the good fish and throwing the bad fish away.
In the , it is related that the disciples fished all night but caught nothing. Jesus instructed them to cast the nets on the other side of the boat, and they drew in 153 fish. It has been observed that, like many other numbers given in the Bible, this number is associated with a mystic property, in this case the vertical ratio of the shape known as the vesica piscis.
A less commonly cited use of fish in Christ's life may be found in the words of , in which, upon being asked if his Teacher does not pay the temple (two-drachma) tax, Simon Peter answers, "Yes." Christ tells Peter to go to the water and cast a line. He says that a coin sufficient for the tax will be found in the fish's mouth. Peter does as told and finds the coin.
Societies of Christians in Hellenistic Greece and Roman Greece, prior to the Edict of Milan, protected their congregation by keeping their meetings secret. In order to point the way to ever-changing meeting places, they developed a symbol which adherents would readily recognize, and which they could scratch on rocks, walls and the like, in advance of a meeting. At the time, a similar symbol was used by Greeks to mark the location of a funeral, so using the ichthys also gave an apparent legitimate reason for Christians to gather.
According to Robert Mills, the earliest known literary reference to the ichthys as a symbol of primitive Christianity was made by Clement of Alexandria (c.150-c.215), but the ichthys is also seen in first century catacombs in Rome. Christianity Today explained that Christians, when threatened by Romans in the first centuries after Christ, used the fish symbol to mark meeting places and tombs, or to distinguish friends from foes. The publication cites one ancient explanation, still popular today:
There are several other hypotheses as to why the fish was chosen. Some sources indicate that the earliest literary references came from the recommendation of Clement of Alexandria to his readers (Paedagogus, III, xi) to engrave their seals with the dove or fish. However, it can be inferred from Roman monumental sources such as the Capella Greca and the Sacrament Chapels of the catacomb of St. Callistus that the fish symbol was known to Christians much earlier. This Christian symbol might well have been intended to oppose or protest the pagan apotheosis of the Roman emperor during the reign of Domitian (AD 81 - AD 96). Coins found in Alexandria referred to him as Theou Huios (Son of God). In fact, even earlier, since the death and deification of Julius Caesar, Augustus (Octavian) already styled himself as divi filius, son of the divine (Julius), and struck coins to that effect. This practice was also carried on by some of the later emperors. Another probable explanation is that it is a reference to the scripture in which Jesus miraculously feeds 5,000 people with fish and bread (, , and ). The ichthys may also relate to Jesus or his disciples as "fishers of men" (e.g., ). Tertullian, in his treatise On Baptism, makes a pun on the word, writing that "we, little fishes, after the example of our ΙΧΘΥΣ Jesus Christ, are born in water.
Some theories about the Historicity of Jesus suggest that Christianity adopted certain beliefs and practices as a syncretism of certain mystery religions such as Mithraism, and that this may be the origin of the ichthys in Christian circles.
Barbara Walker in particular hypothesizes in her book, The Woman's Dictionary of Symbols and Sacred Objects, that the Ichthys was the son of the pagan sea goddess Atargatis. She also posits that the Ichthys symbol was a representation of sexuality and fertility. Christian scholars accept this historic link, while others disagree.
Traditionally, up-coming events at the university were advertised in chalk on the bitumen paths. The campaign for the Fish Mission began by drawing the ichthus symbol on pavements all around the university. Silk-screen prints in bright colours on a white background were stuck with flour glue to the rises of walkway stairs throughout the campus. The unexplained early campaign provoked much speculation and interest. Querulous cartoons appeared in the student newspaper Honi Soit. As the advertising campaign progressed, more information was revealed.
Following the success of the Fish Mission publicity campaign, the Australian Fellowship of Evangelical Students used the symbol more widely on campuses around Australia. From Christian Unions of students it quickly spread to the churches.
The symbol was rapidly adopted for use by other Christian bodies within Australia such as the Church Mission Society from whose shop near St. Andrew's Cathedral, Sydney could be purchased small items of jewelry with the ichthus motif. From Sydney the use of the motif was taken to Asia by university students who had been resident at International House which had close ties with the A.F.E.S.. The ichthys symbol was soon in use among Christians across the world.
Distortions of the Ichthus symbol in popular culture rely on its use as a symbol of Christianity.: