The Celtic Cross is well represented in the Book of Kells and other manuscript illustrations – many of them religious texts – and carved stone crosses with the familiar intertwined lines and zoomorphic figures of Celtic art may still be found all over the British Isles, in Scotland in particular.
As symbolic expressions, the circle and the cross could not be more different. One is mystical while the other is almost geographical. The circle is a symbol of eternity and the endlessness of God’s love, while the cross relates to the four directions, or four corners of the Earth (or perhaps the four elements: Air, Earth, Fire, Water), while the axes coming together imply the joining of forces such as Heaven and Earth. That coordinate, enclosed within the circle, suggests a realm where time & space cease to exist, a precondition for communication between this world and beyond.
Despite its long history, the cross has been well adopted by Christianity, but that does not mean its ancient meanings have altogether vanished. Just as the swastika became a symbol for hate, overriding its former associations, the original meanings of the cross and circle are waiting to be rediscovered. As a tattoo design it may have different meanings for different peoples, but at its symbolic roots it is a design that powerfully evokes the spiritual nature of the universe.