Full Idea
By essentialism about individuals I simply mean the view that individual things have essential properties, where an essential property of an object is a property that the object could not have existed without.
Gist of Idea
An individual essence is the properties the object could not exist without
Source
Penelope Mackie (How Things Might Have Been [2006], 1.1)
Book Reference
Mackie,Penelope: 'How Things Might Have Been' [OUP 2006], p.1
A Reaction
This presumably means I could exist without a large part of my reason and consciousness, but could not exist without one of my heart valves. This seems to miss the real point of essence. I couldn't exist without oxygen - not one of my properties.