Which is better, Sorcery or Knowledge?

Sorcery is better for Chaos and Summoning magic, while Knowledge is better for Light and Darkness. But don't overdo it with Knowledge, as mages sometimes have hundreds of mana for cheap and weak spells.

The topic itself is somewhat strange; it all depends on which race and hero you are playing. For example, for a mage, Knowledge is always the priority, so it's preferable to take Sorcery on various alternative upgrade options. For Dungeon, it's the opposite. As for the mage and his Knowledge, it's impossible to have too much, and the more he has, the better, because it directly affects the level of mini-arts.