theory of behaviourism - or, to give it its full title, logical behaviourism
- holds that being in a mental state (such as being happy) is the
same as being in a physical state. In other words, since all that
we can know about another person's state of mind is through their
behaviour, there is nothing else.
believe that any statement about the internal or private world of
individuals may be translated into a statement about publicly observable
actions. For instance, if I say, "I am happy", this may
be translated into a description of my physical state - increased
heart rate, smiling, etc. If none of these things were present -
the behaviourist would argue - then the person is not really happy.
Obviously, emotions are not always accompanied by extravagant outward
signs, but even quieter forms of emotional or mental state must
be translatable into some form of physical condition.