|Credit: Edana A.|
This is a line from a 8th or 9th century poem by an Irish monk, called Pangur Ban. In the poem, the monk talks about how he sits up at night writing while his white cat, Pangur Ban, hunts mice. ("Ban" means "white" in Irish Gaelic.)
Another word for the process of "turning darkness into light" is "illumination." Additionally, this word can also refer to the practice of decorating and embellishing text with designs. Perhaps the most well known example of an illuminated manuscript is The Book of Kells.
The line and the cat also appear in the film, The Secret of Kells. (See The Secret of Kells)
In the film, Brendan learns the art of illumination and uses his skill to work on the legendary Book of Kells. Pangur Ban, a white cat who accompanied Brother Aiden from the Isle of Iona, joins Brendan on his adventures and becomes his friend.
Obviously, the poem was an inspiration for the film, for during the credits, the poem is read aloud in Irish.
To most, darkness means ignorance and light symbolizes truth and knowledge. Think of the word "enlighten."
Although not mentioned specifically in film or poem, the phrase, "turning darkness into light," has a very profound significance, evoking Biblical truths. While the monks illuminate (enlighten) by preserving and sharing the Bible, it is Jesus who ultimately turns darkness into light. Jesus said,“I am the light of the world. Whoever follows me will never walk in darkness, but will have the light of life.” John 8:12
Link to Pangur Ban and additional background on the poem: Irish Culture and Customs