Page:Ethics (Moore 1912).djvu/207

 impossible. Or, to take another instance: It is true, as a rule, that cats can climb trees, whereas dogs can’t. Suppose that on a particular afternoon neither A’s cat nor B’s dog do climb a tree. It is quite absurd to say that this mere fact proves that we must be wrong if we say (as we certainly often should say) that the cat could have climbed a tree, though she didn’t, whereas the dog couldn’t. Or, to take an instance which concerns an inanimate object. Some ships can steam 20 knots, whereas others can’t steam more than 15. And the mere fact that, on a particular occasion, a 20-knot steamer did not actually run at this speed certainly does not entitle us to say that she could not have done so, in the sense in which a 15-knot one could not. On the contrary, we all can and should distinguish between cases in which (as, for instance, owing to an accident to her propeller) she did not, because she could not, and cases in which she did not, although she could. Instances of this sort might be multiplied quite indefinitely; and it is surely quite plain that we all of us do continually use such language: we continually, when considering two events,