 One obvious response to this objection is to reject extensionality (Thomson 1983). However, this move comes at a cost since it requires giving up on classical  mereology.  A second response is to deny that objects like David and Lump share all their material parts. For example, Baker (2000, p. 81) suggests that David’s nose is a part of David, but not a part of Lump. A third response is to grant that coinciding objects share all their material parts, while insisting that they differ in some non-material aspect (see, for example, Rea 1998, McDaniel 2001. Paul 2002, Koslicki 2008, and Brower 2014). The most familiar version of this view traces back to Aristotelian idea that material objects are compounds of matter and form (see  Aristotle’s metaphysics).