We distinguish || There is the case when a person reacts to the letters he sees in the ‘correct’ way never having seen this piece of print before reading his newspaper and the case where he knows what is before him by heart he has never been able to read & now just looks at the piece of paper & speaks || says the piece by heart. Or he can read but slowly & with pain but he knows the piece by heart or almost by heart & he looks at the words in a sense half reading half saying by heart (reading music).
Or he looks at the paper & has a conversation he is not guided.
     Totally different from the experience of normal quick reading is that of reading a new script, here we have most characteristic experiences of reading whereas in the other case we haven't. Of a man who reads his newspaper we may say that many words he doesn't read.
     Sometimes it is the personal experience which clearly distinguishes reading from not reading: e.g. when A cheats you & pretends he is reading his personal experience is certainly different from that if he were reading. We say here surely he knows whether he is reading or not & so reading seems a peculiar personal experience
But this doesn't follow. Of course when B is reading a newspaper he has not the personal experience of a man pretending to read. On the other hand there are all sorts of characteristic experience connected with reading.
     Dream reading. Imagine a person who while reading had the experience of saying by heart. Should we say he was reading or not?
“Only he can know whether he is reading”. This applies if by reading we mean personal experience.