“应当意味着能够”(Ought implies can)这一命题在道德哲学讨论中经常为人们提及或征引,且往往被视为当然。之所以往往被视为当然,似乎在于它给人这样一种直觉上的确信,即当我们陈述“P应当做M”时,这意味着“P能够做M”。然而,这种直觉确信也许并不完全可靠,我们还需对之作进一步的限定。 The “Ought implies can” proposition is often referred to or referred to by people in moral philosophical discussions, and is often taken for granted. The reason why it is often taken as a matter of course seems to be that it gives people an intuitive conviction that when we state that “P should do M”, this means that “P can do M”. However, this intuitive assurance may not be entirely reliable, and we need to further restrict it.