1. Hempel’s philosophical behaviourism
Michael Lacewing
© Michael Lacewing

2. Philosophical behaviourism
A family of theories that claim that we can analyse mental concepts in terms of concepts that relate to the body, and in particular, the concept of ‘behaviour’
Focus not on metaphysics – what exists – but on language – mental concepts
Before we do metaphysics of mind, we need conceptual analysis
© Michael Lacewing

3. Methodological behaviourism
A theory about how a scientific psychology works (Watson, Skinner)
To be properly scientific, psychology must deal with what can be observed, not what cannot
Therefore, psychology should aim only at the explanation and prediction of behaviour without appealing to ‘inner’ mental states
A claim about science and about how we know about mental states
© Michael Lacewing

4. Philosophical behaviourism
What we are talking about when we are talking about the mind and mental states is behaviour
Our psychological terms are about what people do, and how they react
‘The mind’ is not a thing
Different kinds of philosophical behaviourism
Hempel: ‘logical’, ‘analytical’, ‘hard’ behaviourism
But sometimes ‘logical’ = ‘philosophical’!
Ryle: ‘soft’ behaviourism
© Michael Lacewing

5. Hempel on meaning What is the meaning of a scientific statement?
To know the meaning of a statement is to know the conditions under which we would call it true and those under which we would call it false
So ‘the meaning of a statement is established by the conditions of its verification’ = the observations that we can make to check its truth
First implication: if we can’t, in principle, empirically check the truth of the statement, it is meaningless
© Michael Lacewing

6. Hempel on meaning
Second implication: two statements have the same meaning if they are both true or both false in the same conditions
They have the same conditions of verification
Third, we can translate a statement into a series of statements that simply describe the conditions of verification
Translation: a statement with the same meaning, but expressed in different words or concepts
E.g. a statement with the concept TEMPERATURE can be translated into a series of statements describing the observations we make to establish whether the first statement, using TEMPERATURE is true
© Michael Lacewing

7. The meaning of psychological statements
The meaning of ‘Paul has a toothache’ (or any other psychological claim) is its conditions of verification
Unless we can verify it empirically, it will be meaningless
Conditions of verification:
‘Paul weeps and makes gestures of such and such kinds.’ [bodily behaviour]
‘At the question “What is the matter?”, Paul utters the words “I have a toothache”.’ [linguistic behaviour]
‘Closer examination reveals a decayed tooth with exposed pulp.’ [physical bodily states]
‘Paul’s blood pressure, digestive processes, the speed of his reactions, show such and such changes.’ [physiological changes]
‘Such and such processes occur in Paul’s central nervous system.’ [brain processes]
© Michael Lacewing

8. The meaning of psychological statements
So psychological statements can’t be about private states of the person
They only have meaning if they can be publicly checked
So they must be about physical and behaviour states
These conditions of verification give us the meaning of the psychological statement
The conditions of verification don’t tell us only how we know, but what psychological concepts mean
So psychological statements can be translated, without changing the meaning of what is said, into statements that only use physical concepts
© Michael Lacewing

9. Implications
There is no ‘essence’ to mental states that distinguish them from what is physical
Talk of mental states just is talk of behaviour and physical bodily changes
So there is no question of the mind-body interaction
This is not eliminativism – rather than say mental states don’t exist, Hempel says that there is no real question of whether they exist
To say ‘pain exists’ or ‘there are beliefs’ is to say that we can make certain observations of the person’s behaviour
© Michael Lacewing