Themed Seminar Autumn 2026
Starts:
Finishes:
Venue:
Birkbeck Central
No booking required
Themed seminar on Truth
This seminar series proposes an account of what it is for a sentence to be true. Beginning with the mental relations of consciousness and judgement, supposed irreducible, the account invokes the metaphysics of properties and events to develop a theory of propositions. When the theory of belief and desire is added, we arrive at a picture theory of language in the style of the Tractatus. By widening the concept of fact to include timeless facts as well as events, this picture theory can be extended to apply to any sentence formalisable in the predicate calculus.
Seminar 1: Consciousness and judgement (8 October, Birkbeck Central BCB 405).
An animal is an organism that is capable of consciousness. A rational animal is an animal that is capable of judgment. Consciousness is a relation to an event, and is therefore inerrant, since we cannot stand in a relation to something that does not exist. But judgement is a relation to a type of event, so it is error if there is no event of that type. Truth is the property some words have, if they express a judgement that is not error.
Seminar 2: Properties (22 October, Birkbeck Central, BCB 211)
According to Aristotle, every judgement is of subject-predicate form. The predicate of the judgement is a single object, the subject is one or more other objects. This introduces a category distinction of fundamental importance: a property is the kind of object that can be the predicate of a judgement. The property and the other objects are united in the judgement, but are they also united in reality? If so, what unites them? This is Plato’s problem of ‘participation’– what is it for an object to exemplify a property?
Seminar 3: Events and propositions. (5 November, Birkbeck Central BCB 405)
Kim’s theory of events might seem to solve Plato’s problem. Kim says an event is the exemplification of a property by a substance at a time. So a substance exemplifies a property if there occurs the event that is the exemplification of that property by that substance. Kim takes an event to be a single entity, a ‘complex structure’, the constituents of which are a property, a substance and a time. But he does not tell us what binds the ‘constituents’ into a single whole, so his theory runs into the notorious problem of Bradley’s Regress. We can evade Bradley if we take the property, substance, and time to be the identifiers of an event type, not constituents of an event token. Define a proposition as any sequence of a property, object, and time. Then a proposition identifies a type of event, and a judgement with that proposition as its content is error if the type has no token.
Seminar 4: Belief and desire (19 November, Birkbeck Central BCB 405)
Like judgements, beliefs and desires have propositions as their contents. Judgements are conscious, but we are not conscious of our beliefs and desires, though we can know we have them by observing our behaviour. Language allows us to transmit beliefs from one person to another. We can express our belief by uttering a sequence of words, thereby evincing a desire that the belief our words express should become the belief of the hearer. If the belief is not in error, we call the sequence of words true.
Seminar 5: A picture theory semantics (3 December, Birkbeck Central BCB 405)
A sentence of colloquial language that attributes a property to a substance at a time can be formalised as a sequence of names, i.e., the name of the property, the name of the substance and the name of the time. Corresponding to the sequence of names is the proposition that is the sequence of their referents. The proposition identifies a type of event, and the sentence is true just in case a token of the type exists. Thus an atomic sentence of a colloquial language serves as a semantic ‘picture’ of a type of event. An event is a temporal fact, and we can extend the picture theory to timeless truths by taking them to correspond to timeless facts. Truths that contain logical constants are timeless, and can be taken to correspond to logically complex facts, for example, negative facts, conjunctive facts and general facts.
Contact name: Keith Hossack
Tags: