But suppose I say: ‘I have the same sensations now as five minutes ago’ – what criterium of identy am I
using? – What criterium am I using for determining that what I feel is pain, or ˇthat what I see is red? None. There are criteria which can convince me that I am using the word ‘red’ or ‘pain’ as they are normally used in English. I can point to something & say: ‘The colour of this you do call ‘mauve’, don't you?’ etc.