more on this theme | more from this thinker | more from this text
Full Idea
There seems to be surface synonymy between 'is essentially' and de re occurrences of 'is necessarily', but intersubstitution often fails to preserve sense (as in 'Winston is essentially a cyclist' and 'Winston is necessarily a cyclist').
Gist of Idea
'Is essentially' has a different meaning from 'is necessarily', as they often cannot be substituted
Source
Ruth Barcan Marcus (Essential Attribution [1971], p.193)
Book Ref
-: 'Nous' [-], p.193
A Reaction
Clearly the two sentences have different meanings, with 'essentially' being a comment about the nature of Winston, and 'necessarily' probably being a comment about the circumstances in which he finds himself. Very nice. See also Idea 11186.
Related Idea
Idea 11186 'Essentially' won't replace 'necessarily' for vacuous properties like snub-nosed or self-identical [Marcus (Barcan)]