What I am maintaining is the common-sense view, which seems obviously true, that it may be true that A has in fact got P and yet also true that A might have existed without having P. And I say that this is equivalent to saying that it may be true that A has P, and yet _not_ true that from the proposition that a thing has _not_ got P it _follows_ that that thing is _other_ than A--numerically different from it. And one reason why this is disputed is, I think, simply because it is in fact true that if A has P, and _x_ has _not_, it _does_ follow that _x_ is other than A. These two propositions, the one which I admit to be true (1) that if A has P, and _x_ has not, it _does_ follow that _x_ is other than A, and the one which I maintain to be false (2) that if A has P, then from the proposition with regard to any term _x_ that it has not got P, it _follows_ that _x_ is other than A, are, I think, easily confused with one another. And it is in fact the case that if they are not different, or if (2) follows from (1), then no relational properties are external. For (1) is certainly true, and (2) is certainly equivalent to asserting that none are. It is therefore absolutely essential, if we are to maintain external relations, to maintain that (2) does _not_ follow from (1). These two propositions (1) and (2), with regard to which I maintain that (1) is true, and (2) is false, can be put in another way, as follows: (1) asserts that if A has P, then any term which has not, _must_ be other than A. (2) asserts that if A has P, then any term which had not, _would necessarily be_ other than A. And when they are put in this form, it is, I think, easy to see why they should be confused: you have only to confuse "must" or "is necessarily" with "would necessarily be." And their connexion with the question of external relations can be brought out as follows: To maintain external relations you have to maintain such things as that, though Edward VII was in fact father of George V, he _might_ have existed without being father of George V. But to maintain this, you have to maintain that it is _not_ true that a person who was _not_ father of George would necessarily have been other than Edward. Yet it is, in fact, the case, that any person who was not the father of George, _must_ have been other than Edward. Unless, therefore, you can maintain that from this true proposition it does _not_ follow that any person who was _not_ father of George _would necessarily_ have been other than Edward, you will have to give up the view that Edward might have existed without being father of George.