ABSTRACT
In the tradition of Aristotle, logicians before Frege distinguished in every assertoric sentence three constituents. Boole’s logic is a representative example of this view:
Boole holds that every primary affirmative proposition – a proposition that is not about propositions – has a unique tripartite analysis into subject, copula and predicate. Such a proposition states a relation between the extensions (Boole calls them ‘collections’) of the subject and predicate. The copula is a sign of affirmation and carries assertoric force. It turns a collection of concepts into a proposition that represents things as being a certain way.
