The Humean mosaic refers to totality of all facts and properties of the world in four-dimensional spacetime, within which there is no metaphysical distinction between scientific laws and other proposition. This view is invoked in the descriptivist account of scientific laws as true propositions that jointly maximize concision and informativeness. David Lewis calls this view Humean supervenience:
“All there is to the world is a vast mosaic of local matters of particular fact, just one little thing and another” (1986b: ix).
Specifically, Humeans believe that scientific laws supervene on particular facts about the world. This has the specific advantage of giving a clear epistemological account of how science can discover laws in the first place: we can read law-like statements directly from particular observations.