Richard Boyd constructed a counter-argument to Kripke’s brand of property dualism. In the example of pain, Kripke would argue that our perception of pain is the non-physical manifestation of the physical process of C-fibres firing.
However, there have been incidents where pain has been felt without the physical process of C-fibres firing. Think of amputee victims who still experience pain in phantom limbs. This non-physical perception of pain, without the physical occurrence of C-fibres firing suggests that mental properties cannot be reduced to components of physical phenomena.