The Structure of Substances: Why Some Properties Are Essential

Many philosophers distinguish between the essential and accidental properties of people, animals, artefacts, species, chemical substances and other things. Other philosophers dismiss this distinction as arbitrary and groundless. I shall explain how substances are items whose instances share many properties, and how any such substance must have one super-explanatory property that accounts for this multiple sharing of other properties. I then argue that essential properties are just those properties that are super-explanatory.