Consider the following case.  Human beings or creatures of some other kind are used by us as reading-machines.  They are trained for this purpose.  The trainer says of some that they can already read and of others that they cannot yet do so.  Take the case of a pupil who has so far not taken part in the training: if he is shewn a written work he will sometimes produce the right sort of sound, and here and there it happens 'accidentally' to be roughly right.  A third person hears this pupil on such an occasion and says: "He is reading."  But the teacher says: "No, he isn't reading; that was just an accident."--But let us suppose that this pupil continues to react correctly to further words that are put before him.  After a while the teacher says: "Now he can read!"--But what of that first word?  Is the teacher to say: "I was wrong, and he did read it"--or: "He only began to read later on"?--When did he begin to read?  Which was the first word that he read? This question makes no sense here.  Unless, indeed, we give a definition: "The first word that a person 'reads' is the first word of the first series of 50 words that he reads correctly" (or something of the sort).

If on the other hand we use "reading" to stand for a certain experience of translation of marks to spoken sounds, then it certainly makes sense to speak of the first word that he really read.  He can then say, e.g. "At this word for the first time I had the feeling: 'now I am reading.'"

Or again, in the different case of a reading machine which translated marks into sounds, perhaps as a pianola does, it would be possible to say: "The machine read only after such-and-such had happened to it--after such-and-such parts had been connected by wires; the first that it read was . . ."

But in the case of the living reading-machine "reading" meant reacting to written signs in such-and-such ways.  This concept was therefore quite independent of that of a mental or other mechanism.--Nor can the teacher here say of the pupil: "Perhaps he was already reading when he said that word."  For there is no doubt about what he did.--The change when the pupil began to read was a change in his behaviour; and it makes no sense here to speak of 'a first word in his new state.'