 We must ask concerning any situation involving this relation (e.g., a exemplifying [Greenness]) what the relata are. One of them is a universal. What is the other? It will obviously not do to reply—a grum (defined as an instance of [greenness]); for this would amount to saying that the relatum in question is that which stands in the instancing relation to [Greenness]; true enough but hardly enlightening. It still leaves open the question—what is it that stands in the instancing relation to [Greenness]? …the only alternative left appears to be a ‘bare’ particular, or what I prefer to call a substratum. Once we see the need for supplying an entity to which the universal involved bears the relation of being exemplified, we can see that only a bare particular would do the job. (1954: 255)