 On this standard definition, artifacts must satisfy three conditions. They must be intentionally produced, thus ruling out unintended by-products of intentional actions, such as the shavings that result from woodcarving, as well as all naturally occurring objects, such as salamanders and stars. They must involve modification of materials, thus ruling out naturally occurring objects even when used intentionally for a purpose, such as sticks thrown to amuse your dog. And they must be produced for a purpose. This rules out intentionally modified objects that are nevertheless not intended to accomplish any further goal, such as the scraps produced when you intentionally, but for no particular reason, tear up a piece of paper before throwing it away. Presumably, then, these three conditions are intended to be individually necessary and jointly sufficient to distinguish artifacts from naturally occurring objects.