Confusing generic essence with exhaustive inclusion causes a major interpretive error. Generic essence concerns what a kind is; exhaustive inclusion concerns the extension of a claim to every member of the relevant class.
AspectGeneric essenceExhaustive inclusion
FocusNature or classAll its relevant members
Guiding questionWhat kind is this?Who exactly is included?
Contextual clueDefinition or generic comparisonCompleteness or exception
Both uses involve definite nouns, but definiteness alone does not prove that a proposition encompasses every individual.