  Russell (e.g., 1940, Chapter 6) held that a substance just is a bundle of universals themselves related by a special relation between properties, known as compresence. If the universals in question are taken to be intrinsic properties, then Russell’s theory implies the Strong Principle. (At least it seems to imply it, but see O’Leary-Hawthorne 1995, Zimmerman 1997 and Rodriguez 2004.) And if the status of substances is non-contingent then it implies the necessity of the Strong Principle. This is important because the most vulnerable version is clearly the Strong when it is held to be non-contingent. (See also Armstrong 1989, Chapter 4.)