Darn straight. And then colonize or subjugate any existing populations. I think the books obliquely addressed this by having one of the major civilizations men

Darn straight. And then colonize or subjugate any existing populations. I think the books obliquely addressed this by having one of the major civilizations mention a comparable civilization that was its antagonist. But even so, subjugation or incorporation of other intelligent species shouldn't have been impossible.