It is not a coincidence that every red rose is coloured. No rose can be red without being
coloured. A red rose is coloured in virtue of its being red its being coloured is
metaphysically explained by its being red. This is at least in part underwritten by what it
is for the rose to be coloured by the nature - or essence - of its being coloured. If this is
right then questions concerning possibility and necessity questions concerning metaphysical
explanation and questions concerning essence are systematically connected. This book proposes
a unified account of metaphysical modality grounding and essence. It develops a semantic way
to model essences as localised necessities that rule out worlds as impossible and uses it to
account for grounding and metaphysical modality.
