 Sperber concludes that “artifact” as a theoretical term cannot be usefully defined, as any attempt to do so will be frustrated by the continua detailed above. We may call this the continuum problem. This concern is echoed by Kathrin Koslicki (2018), who notes that the common reliance on creators’ intentional activity to distinguish artifacts from naturally occurring objects inevitably leaves us with objects such as unintended by-products and naturally occurring objects pressed into service for human purposes which do not seem to fall readily into either category. She does not think that current approaches in metaphysics have the resources to deal with such puzzles about artifacts, and concludes that further development of these approaches is necessary. For Sperber—whose training is in anthropology—the lesson is that the social sciences simply do not need “artifact” as a term of art. But philosophers, and some other social scientists, have reacted to the continuum problem by doubling down on their classification efforts. Risto Hilpinen (2011), following the anthropologist Wendell Oswalt (1973; 1976), uses the term “naturefact” for naturally occurring objects used intentionally, but without modification, for some purpose. Naturefacts thus lie between naturally occurring objects and artifacts on the continuum. Hilpinen also suggests that what he calls “residue”—modified but unintended by-products of productive activity, such as sawdust—are a conceptually distinct category of objects also lying somewhere between artifacts and naturally occurring objects. (A terminological note: in archaeology, “naturefact” is more usually used to mean an object that is in fact the result of purely natural processes, but is difficult to distinguish from an intentionally modified object. This is a problem that bedevils paleoarchaeologists studying stone tools, in particular (Schnurrenberger &amp; Bryan 1985). Archaeologists also sometimes distinguish artifacts from ecofacts—organic or inorganic remains of archaeological significance that have undergone no, or minimal, modification by humans, such as animal bones, stored grain, pollen, charcoal, and the like. Naturefacts and residues in Hilpinen’s sense are usually included in the ecofact category.)