So he can make sure of what it means in this private way‘!|in this private way of what it means by having a private sensation Making sure that you know what ‘seeing

red’ means is good only if you can make use of this knowledge in a future case. Now what if I see a colour again, can I say I made sure I knew what ‘red’ was|meant so now I shall know that I'll recognize it correctly? In what sense is having said the words ‘this is red’ before a guarantee that I now see the same colour when I say again I see red?