The Mind-Brain Type Identity Theory Michael

Type identity theory ‘Type’ identity
Mental types of thing are actually physical types of thing
They don’t seem the same because we have different ways of knowing about them
Science throws up some surprising claims © Michael Lacewing<br>

Identity v. correlation Identity is not correlation
Hearts and kidneys; size and shape
Neuroscience can only establish correlations
This is not enough to support identity theory
Philosophy: Appeal to Ockham’s razor: don’t multiply entities beyond necessity
The identity claim is not analytic or conceptual
The claim is not that ‘pain’ means ‘the firing of nociceptors’
But that two distinct concepts pick out just one property (like water and H2O) © Michael Lacewing<br>

Reduction Ontological reduction: the things in one domain (e.g. mental things) are identical with some of the things in another domain.
Heat is mean molecular kinetic energy
There is nothing more to a mental property than being a particular physical property © Michael Lacewing<br>

Multiple realizability Putnam: Mental properties are not identical to physical properties because the same mental property can be ‘realized by’ different physical properties
‘Realise’: ‘to give actual form to’, ‘to make real’
e.g. the brain states that relate to pain are different in different species, but pain is the same mental state.
Suppose pain = N1 in humans, but pain = N2 in dogs. Since pain = pain, then N2 = N1. If N2 ≠ N1, then the dog is not in pain!
The dog is in pain. So either N1 or N2 can realise pain, but because N2 ≠ N1, neither N2 = pain nor N1 = pain © Michael Lacewing<br>

Multiple realizability A priori form:
It is conceivable, and therefore possible, for a being with quite a different physical constitution from us to have the same thoughts or sensations.
But it is inconceivable, and therefore impossible, for something both to have and not have a certain property.
Therefore, mental properties can’t be the same as physical properties. © Michael Lacewing<br>