When regarded as a slippery, smooth-furred creature which shuns humans and slips through their fingers, the seal is the symbol of a virginity inspired not by higher motives, but by fear of self-surrender and by lack of love. Thus, in Greek legends, nymphs pursued by gods changed themselves into seals. The sea-god, Poseidon, had flocks of seals of which he made the minor deity, Proteus, the shepherd, the latter having the power to change himself into whatever shape he wished. Today, seal symbolism may be described with greater clarity. Seals symbolize the unconscious or at least that portion of it which derives from repression, carefully controlled by Proteus, but, like its shepherd, capable of taking any form it chooses.
Legends also tell of female seals stripping off their skins on the sea-shore and walking the sands in the shapes of lovely women.
Kings put their seals upon documents setting out their decrees. Seals are thus marks of power and of authority. A seal has the force of a signature. Seals authenticate public or private contracts. They reserve such documents as wills for future publication, hence to seal means to lock away, to lay aside and preserve. Seals thus become symbols of secrecy.
Seals mark people or things as the unquestionable property of those whose stamp they bear and under whose protection they stand by the same right. Seals are symbols of lawful ownership.
These different uses are the theme so richly developed in symbolic variations.
Thus St Paul regarded the church in Corinth as the legitimation of his apostolate ‘for the seal of mine apostleship are ye in the Lord’ (1 Corinthians 9: 2). The Father marked the Son with his seal, indicating thereby that he had chosen him and sent him in his name to bestow eternal life (John 6: 22).
God seals his instructions (Job 33: 16); he sets a seal upon the stars forbidding them thereby to show themselves (Job 6:7). He commands Daniel to seal his visions, in other words, to keep them secret (Daniel 12: 4; see also Revelation 22: 10). On the other hand St John (Revelation 22: 10) was not to seal the revelations made to him since they were of immediate effect.
Rabbinical writers regarded the seal as the symbol of circumcision, initiating the individual into God’s people. St Paul takes this a step further by explaining that true spiritual circumcision is a seal of membership of the righteous (Romans 4: 11) and that the Holy Spirit may be termed a seal in so far as it is a pledge of salvation (2 Corinthians 1: 22). Hence, it is a short step from this to acknowledgement that the divine seal possesses semi-magical properties, a step often taken at different and widely separated periods of time, as witness the seal-charms bearing the Tetragrammaton (God’s name in Hebrew). That these properties were undoubtedly those of preservatives against evil is apparent from Mandean and Gnostic writings.
God marks individuals with his seal (Ezekiel 9: 4; Revelation 7: 3ff.) showing thereby that they belong to him and are under his protection. In this context, the author of Revelation would seem in all probability to have in mind the letter X (that is to say chi, the initial letter of Christ’s name in Greek). Even in this context, the word ‘seal’ begins to return to a realist meaning without, however, losing any of the symbolic load it has gathered on the way.
In fact, while Christianity subsequently continued to use the word ‘seal’ in the sense or senses indicated above, it began to use it as well with a new and technical meaning. Hermes states that the seal is water, and by water should be understood the water of baptism. Irenaeus, Tertullian and Clement of Alexandria all understood this sense of the word, so that in the end ‘seal’ was made the technical term for baptism. Was it not this which marked the individual as belonging to God, who justified and protected that person? It is quite possible that, very early on, the ceremony of baptism itself incorporated that clear rite of deposition to be found at the end of the second century in the Apostolic Tradition of Hippolytus. (See, for example, baptismal rituals and liturgies.)
The Gnostics were to speculate about the symbol and to see in the seal the mysterious means whereby the soul was safeguarded during its journey through the lower worlds to the light on high.
To close this line of thought, mention should be made of an interesting development of the seal symbol by Philo of Alexandria, who regarded the seal as the idea, the model, which stamps the world of the senses. The primeval seal was, therefore, the ideal world, the Word of God (On the Creation of the World 25). Plato’s influence is all too evident.
Lastly, there is a passage in Revelation which speaks of a book with seven seals (Revelation 5ff.), of which the interpretation raises difficult questions. To determine the symbolism of the image, one has first to decide on what the book represents - is it the Book of Fate, God’s testament, or the Old Testament, hitherto misinterpreted? Whatever the document may be, it should be noted that it can only be opened by a person invested with absolute divine authority - the Lamb, Christ himself.
The betrothed in the Song of Solomon says of his beloved: 'Set me as a seal upon thine heart, as a seal upon thine arm: for love is strong as death.' The commentators in the Jerusalem Bible remark: 'The seal, attesting the wishes of its owner, here symbolizes the wishes of Yahweh, i.e. the Law' and Jehovah is a jealous god. The passage could be interpreted in a more inward-looking way if the seal were taken as being the symbol of ownership. The lover does not force his law of faithfulness, he invites the bride to imprint upon her heart and arms, in letters of fire which nothing can put out, the sign of their mutual love which surrenders them into a relationship as decisive as death. This is no longer obedience but willing self-surrender.