If Stephen Hawking were capable and willing of turning the visible universe into copies of himself, I would want to keep him boxed too. At a certain level of risk it is no longer a matter of justice, but a matter of survival of the human species, and likely all other species, sapient or otherwise.
EDIT: To make it clearer, I also think it is “Just” to box a sentient entity to prevent a measure of disutility to an as-of-yet undetermined utility function approximating CEV.
If Stephen Hawking were capable and willing of turning the visible universe into copies of himself, I would want to keep him boxed too. At a certain level of risk it is no longer a matter of justice, but a matter of survival of the human species, and likely all other species, sapient or otherwise.
EDIT: To make it clearer, I also think it is “Just” to box a sentient entity to prevent a measure of disutility to an as-of-yet undetermined utility function approximating CEV.