Philosophical Studies · G. E. Moore
EXTERNAL AND INTERNAL RELATIONS
In other words, though every relational property of the form "having _this_ for a spatial part" is "internal" in our sense, it seems equally clear that every property of the form "is a spatial part of this whole" is _not_ internal, but purely external. Yet this last, according to me, is one of the things which the dogma of internal relations denies. It implies that it is just as necessary that anything, which is in fact a part of a particular whole, should be a part of that whole, as that any whole, which has a particular thing for a part, should have that thing for a part. It implies, in fact, quite generally, that any term which does in fact have a particular relational property, could not have existed without having that property. And in saying this it obviously flies in the face of common sense. It seems quite obvious that in the case of many relational properties which things have, the fact that they have them is _a mere matter of fact:_ that the things in question _might_ have existed without having them. That this, which seems obvious, is true, seems to me to be the most important thing that can be meant by saying that some relations are purely external. And the difficulty is to see how any philosopher could have supposed that it was not true: that, for instance, the relation of part to whole is no more external than that of whole to part. I will give at once one main reason which seems to me to have led to the view, that _all_ relational properties are internal in this sense.
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.
By far the most important point in connexion with the dogma of internal relations seems to me to be simply to see clearly the difference between these two propositions (1) and (2), and that (2) does _not_ follow from (1). If this is not understood, nothing in connexion with the dogma, can, I think, be understood. And perhaps the difference may seem so clear, that no more need be said about it. But I cannot help thinking it is not clear to everybody, and that it does involve the rejection of certain views, which are sometimes held as to the meaning of "follows." So I will try to put the point again in a perfectly strict form. Let P be a relational property, and A a term to which it does in fact belong. I propose to define what is meant by saying that P is internal to A (in the sense we are now concerned with) as meaning that from the proposition that a thing has not got P, it "follows" that it is _other_ than A. That is to say, this proposition asserts that between the two properties "not having P" and "other than A," there holds that relation which holds between the property "being a right angle" and the property "being an angle," or between the property "red" and the property "coloured," and which we express by saying that, in the case of any thing whatever, from the proposition that that thing is a right angle it follows, or is deducible, that it is an angle.
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