 It is customary to distinguish between simple and complex properties, even though some philosophers take all properties to be simple (Grossmann 1983: §§58–61). The former are not characterizable in terms of other properties, are primitive and unanalyzable and thus have no internal structure, whereas the latter somehow have a structure, wherein other properties, or more generally entities, are parts or constituents. It is not obvious that there are simple properties, since one may imagine that all properties are analyzable into constituents ad infinitum (Armstrong 1978b: 67). Even setting this aside, to provide examples is not easy. Traditionally, determinate colors are cited, but nowadays many would rather appeal to fundamental physical properties such as having a certain electric charge. It is easier to provide putative examples of complex properties, once some other properties are taken for granted, e.g., blue and spherical or blue or non-spherical. These logically compound properties, which involve logical operations, will be considered in  §4.1.  Next, in  §4.2  we shall discuss other kinds of complex properties, called structural (after Armstrong 1978b), which are eliciting a growing interest, as a recent survey testifies (Fisher 2018). Their complexity has to do with the subdivisions of their instances into subcomponents. Typical examples come from chemistry, e.g., H2O and methane understood as properties of molecules.