Celtic knots are a variety of (mostly endless) knots and stylized graphical representations of knots used for decoration, adopted by the ancient Celts. These knots are most known for their adaptation for use in the ornamentation of Christian monuments and manuscripts like the 8th century Book of Kells and the Lindisfarne Gospels.
«Ποταμοῖς τοῖς αὐτοῖς ἐμβαίνομέν τε καὶ οὐκ ἐμβαίνομεν, εἶμέν τε καὶ οὐκ εἶμεν.»
«We both step and do not step in the same rivers. We are and are not.»
Heraclitus the Riddler