Logic and Language

Bjørn Jespersen (University of Barcelona, joint work with Manuel Garcia-Carpintero): A critique of act theories of propositions and predication

Speaker: Bjørn Jespersen (University of Barcelona, joint work with Manuel Garcia-Carpintero)
Title: A critique of act theories of propositions and predication
Time: 16:00 - 17:30
Location: AUC room 1.02

**NB there's a change of venue for this talk: it will be in AUC, room 1.02**.

The ‘new thinking about propositions’ presents itself as a marked departure from the sort of realism found in Frege and Russell.

Rather propositions are anchored to human actions of thought and speech while still qualifying as objectively existing entities.

One direction the ‘new thinking’ has branched off into is the act-theoretic one, whose foremost proponents are Scott Soames and Peter Hanks.

The proposition that individual a has property F is identified with the act type that is tokened whenever an agent predicates F of a. A proposition is a predicative act type. Semantics, to generalize, supervenes upon various act types, such as referring to individuals, expressing properties and relations, and predicating properties and relations of individuals or of propositions.

The act-theoretic approach is, in fact, a natural-language variant of so-called computational-operational-procedural semantics, which identifies meaning with a path of often multiple steps from a point of departure (input entities) to a destination (output entity). At least to this extent, act theories pursue a similar tack as the constructivist type theory of Martin-Löf or Tichý’s realist Transparent Intensional Logic.

But the act-theoretic program has still to develop into a regular theory. Of the two, Hanks’s is more detailed and elaborate and will for this reason receive more attention in this talk.

This talk canvasses various open questions, such as:


  • What is the logic that underlies pragmatic acts of predication?
  • Hanks’s default position is that predication is assertion, as content and force are interwoven. But most kinds of propositions (e.g. disjunctive or negative ones) should be devoid of assertoric force. Hanks argues that non-committal predications occur within so-called cancellation contexts. But what is Hanks’s pure content devoid of force? Does he restore the content/force distinction he sets out to abolish? The underlying problem is the so-called Frege-Geach problem.
  • Just how objective are act types? Act-theoretic semantics appears to be characterized by some unacknowledged idealist traits with a Husserlian flavour.




  • Soames argues that predicative contexts are non-extensional contexts. Is this to say that, e.g., truth-functional connectives occur in non-extensional contexts such that, for instance, the conjunctive proposition AÙB is a non-extensional context? Can the truth-functions maintain their truth-table semantics?




Recent literature


Hanks, P. (2015), Propositional Content, Oxford: Oxford University Press.

Jespersen, B. (2015), ‘Should propositions proliferate?’, Thought 4:243-51.

        Jespersen, B. (2012), ‘Recent work on structured meaning and

         propositional unity’, Philosophy Compass 7:620-30.

Jespersen, B. (forthcoming), ‘Is predication an act or an operation?, in:

         Topics in Predication Theory, P. Stalmaszczyk (ed.), Peter Lang GmbH.

King, J., S. Soames, J. Speaks (2014 ), New Thinking About Propositions,

Oxford: Oxford University Press.

Soames, S. (2010), What is Meaning?, Princeton University Press.