SuperSonicSound
Shadowmancer of the Shadow Cabal
Tome of Salvation says ' Arcane Lore and the Divine Lore are mutually exclusive; the study, focus, and mindset required by any Lore Talent is such that you may only use one at a time. For example, an Anointed Priest of Morr who joins the Amethyst Order effectively abandons his faith in favour of scholarly learning, and thus loses access to the Lore of Morr in favour of the Lore of Death. Conversely, an Amethyst Wizard who chooses to become a servant of Morr would set aside his academic approach to working with magic and embrace his faith—using Divine Lore rather than Arcane Lore. '
Volans seems to be talking about sorcery there, note the reference to using divine assistance to avoid miscasts.
That's true but honestly that seems pretty heavily pushed due to not wanting players to game their way into having multiple lores. Especially as the same thing is stated about having a Dark lore like Necromancy which is clearly dumb as at that point you're well past the point of caring about the negative effect it has on your soul.