  These tropes are the building blocks of the world. In his analogy, they provide ‘the Alphabet of Being’ from which the entities belonging to more complex categories—objects, properties, relations, events—can be constructed, just as words and sentences can be built using the letters of the alphabet. Familiar objects such as shoes and ships and lumps of sealing wax, and their parts as revealed by empirical scientific investigation, such as crystals, molecules and atoms, are concrete particulars or things. In Williams’s scheme, each of these consists in a compresent cluster of tropes—the particular thing’s particular shape, size, temperature, and consistency, its translucency, or acidity, or positive charge, and so on. All the multitude of different tropes that comprise some single complex particular do so by virtue of their sharing one and the same place, or sequence of places, in Space-Time. That is what ‘compresent’ means. There is no inner substratum or individuator to hold all the tropes together. The tropes are individuals in their own right, and do not inhere in any thing-like particular. So Williams’s view is a No-Substance theory, or, otherwise described, a theory in which each trope is itself a simple Humean substance, capable of independent existence.