Chaosmancer
Legend
Arcana explicitly represents knowledge about magic. What is in question is whether that knowledge can equate to magical ability. In 4e it explicitly says yes in some ways. 3e and 5e do not have such explicit uses of the knowledge skill.
Never said that they did have explicit uses of Arcana to cast spells. But it seems very very implicit that the two are related heavily in regards to wizard magic.
I mean, Arcana domain cleric is literally a cleric with wizard magic. There is an obvious connection.