Larian Studios Forums Divinity - Original Sin Divinity - Original Sin - General Skill Books?

Sorry to reup topic.

I wonder... it's different as Divine Divinity, so:
Do the spells depend on the level of skills? (I mean, not the level of the player).

So for 'big' spells, do we need to get 5 (level max.) points for skills of abilities? (example: "Summon Air Elemental" needs 4, 5 points in Aerotheurge? Or just 1 point in Aerotheurge + x level of the player?)

Thanks!