 Heytesbury’s RSS may be taken as representative of Oxford Calculators’ speculative/mathematical physics. It links interests in logic, mathematics, and physics. As Curtis Wilson says: “Heytesbury employs the concept of “limit” and “infinite aggregate” with considerable precision and subtlety; and in treating of variable physics quantities, he approaches the ideal of a purely mathematical description” (Wilson 1960: 3). Not only does Heytesbury analyze physical and mathematical problems by means of the techniques of the logica moderna, but he also employs physical and mathematical rules in the analyses of logical or semantic problems of denomination. Heytesbury is mostly interested in the problem of determining under what conditions a subject can be denominated such-and-such, e.g., “white” or “running”. The issue of denomination arises because the attributes of subjects vary in degrees of intensity or completeness. He establishes sets of rules of everyday speech, determining how we denominate a subject under all imaginable circumstances of change. For example, in the sophism Omnis homo qui est albus currit, he concludes that a man is called to be “white” if and only if the external surface of the upper half of him is white (in everyday speech, a man is white if the skin on his face is white) (Wilson 1960: 22–23).