 A variety of particular forms of essentialism have been advocated. Starting at one extreme, there is maximal essentialism. Although Leibniz famously held this view, it nearly goes without saying that this view has had relatively few adherents. According to a less extreme and correspondingly more popular form of essentialism, origin essentialism, an object could not have had a radically different origin than it in fact had. The view that a particular table could not have been originally made from completely different material than the material from which it was actually originally made and the view that a person could not have originated from a different sperm and egg than those from which he or she actually originated are both forms of origin essentialism. Origin essentialism has been defended by Kripke (1972/1980) Salmon (1981), and Forbes (1985), among others. According to another moderate form of essentialism, sortal essentialism, an object could not have been of a radically different kind—at least for certain kinds—than it in fact is. Both the view that being human (or being human if existent) is an essential property of Socrates and the view that Socrates could not have been a credit card account are forms of sortal essentialism. The mildest form of essentialism is minimal essentialism. Mackie (2006) offers a sustained defense of roughly this view.