 This definition requires an understanding of the role—and perhaps the necessity—of intention. Many objects that we presume to be artifacts are not accompanied by human intentions directly. A machine, for example, might automatically hammer out thousands of blades, which the machine stacks into boxes. A particular blade in one of those boxes would typically be considered an artifact even though no human was ever aware of that blade’s existence, to say nothing of having created it for a reason. Millikan (1984) argues that certain entities can be understood as having “derived functions”, when their intended role is part of the explanation for their being reproduced. Thomasson (2003, 2007) develops this idea further, arguing that the function of an artifact is always in principle knowable to the creator. Elder (2004, 2007) develops Millikan’s approach in an opposing direction, arguing that artifacts are copied kinds but need not be accompanied by creator intention.