What Nothing Could Exclude
Two passages from Iain M. Banks turn total instrumental competence into a limit: everything is usable only while it remains inside the model.
“Everything was a weapon” sounds like a doctrine without a blind spot. In Iain M. Banks’s Use of Weapons, materials and people can all be bent to the fight. Nothing is exempt. But the passage gives that appetite a condition: the ability “to find them and choose which one to aim and fire.” Everything is available only insofar as someone knows what to do with it.
Excession supplies the objection. An Outside Context Problem is what civilisations tend to encounter “rather in the same way a sentence encountered a full stop.” The sentence cannot put the stop to work. Its arrival ends the activity in which anything could have been useful.
Read together, the passages turn total instrumentalization into a bounded competence. Special Circumstances can exclude nothing from consideration and still meet something its considerations cannot accommodate. “Everything” means everything within reach of its understanding.
That is a tension between the passages, not an explicit argument Banks makes across the novels. But it puts pressure on the reassurance in Use of Weapons: the operative as “a tooth on the biggest saw in the galaxy.” The tooth knows the force behind it. It need not know what the saw cannot cut.