We cannot say that this belief consists in a relation to a single object, 'Desdemona's love for Cassio', for if there were such an object, the belief would be true. There is in fact no such object, and therefore Othello cannot have any relation to such an object. Hence his belief cannot possibly consist in a relation to this object. Hence it will be better to seek for a theory of belief which does not make it consist in a relation of the mind to a single object. It is common to think of relations as though they always held between two terms, but in fact this is not always the case.
Some relations demand three terms, some four, and so on.
Take, for instance, the relation 'between'. Instances might be multiplied indefinitely, but enough has been said to show that there are relations which require more than two terms before they can occur. The relation involved in judging or believing must, if falsehood is to be duly allowed for, be taken to be a relation between several terms, not between two. This relation, therefore, is a relation of four terms, since Othello also is one of the terms of the relation. When we say that it is a relation of four terms, we do not mean that Othello has a certain relation to Desdemona, and has the same relation to loving and also to Cassio.