Three claims about essential properties are frequently advanced in recent discussions: (1) a property belongs essentially to a thing only if that thing would cease to exist without that property, (2) an essential property is explanatory, And (3) an essential property is such that it must belong to everything to which it belongs. I argue that the "only if" in (1) cannot be changed to "if and only if" and (1) needs to be supplemented by (2), And that (2) is (...) an indispensable feature of aristotle's view of essential properties and that it casts doubt on (3), Although (2) is usually assumed to provide a reason for (3). (shrink)