Abstract
The paper discusses sortal essentialism': the view that some sortal concepts represent essential properties of the things that fall under them. Although sortal essentialism is widely accepted, there is a dearth of theories purporting to explain why some sortals should have this characteristic. The paper examines two theories that do attempt this explanatory task, theories proposed by Baruch Brody and David Wiggins. It is argued that Brody's theory rests on an untenable principle about "de re" modality, while Wiggins' theory appeals to a thesis about principles of individuation that is either unjustified, or vacuous and incapable of supporting sortal essentialism