St. Thomas Aquinas is almost always shown with a sun on his chest. That’s where we got the idea for the undCatholic logo.
But why a sun? What is especially sunny about Aquinas? The short answer is that the sun is a way to symbolize wisdom. Wisdom is “certain and evident knowledge of things through their ultimate causes.” (Aumann, Spiritual Theology, 271)
It means that the wise person knows the way things really are.Just as the sun rises and reveals the world, so too wisdom, when it is present, shows things clearly and truly.