'Aligning' versus 'limiting' versus 'opposing' is a proposed conceptual distinction between ways of getting good outcomes and avoiding bad outcomes, when running a sufficiently advanced Artificial General Intelligence:
For example:
Under the Agents_as_searches view, we can see an agent as embodying computations that search out actions within a domain. The non-adversarial principle then says that we should not be running a search which is looking for ways to hurt us.
We can achieve this desideratum in one of two ways:
If both of these measures fail, then as a fallback second line of defense, we could try to make that search not find anything.
For example: The non-adversarial principle implies that if you build a shutdown button for the AI that suspends the AI to disk when pressed, you must also ensure:
Or:
The first set of measures would be 'alignment'--if those measures work, it's okay for the AI to think here because we think those thoughts are pointed in the right direction. The second approach would be limitation--we don't think the AI's computations are aligned inside this domain yet, so until then, we shouldn't be running computations there.
As a final, strictly fallback line of defense, you could put a big red lever in the computing center that shut off all the electricity even if the AI was failing to suspend to disk. (But you're not relying on this working; it's just there as a maybe-it-might-work measure that might buy you a little more probable safety even if the primary lines of defense failed.)
The alignment/limitation/opposition distinction can help state other ideas from the AI safety mindset. For example:
The principle niceness is the first line of defense can be rephrased as follows: When designing an AGI, we should imagine that all 'oppositional' measures are absent or failed, and think only about 'alignment' and 'limitation'. Any oppositional measures are then added on top of that, just in case.
Similarly, the Omnipotence test for AI safety says that when thinking through our primary design for alignment, we should think as if the AGI just will get Internet access on some random Tuesday. This says that we should design an AGI that is limited by not wanting to act in newly opened domains without some programmer action, rather than relying on the AI to be unable to reach the Internet until we've finished aligning it--even if we plan to later align it sufficiently.