Ryle:

The epistemologist with the usual theoretical habits may bring himself to attend to the ways in which we use task-verbs, and may come to agree that our uses of achievement-verbs are correlated in certain important ways with our uses of task-verbs.  But he will still feel that a theory is being based upon what is exceptional rather than what is regular.  For ordinarily which I report having seen a cow or detected a smell of gas, I cannot, with the best will in the world, report the prior occurrence of a process of scrutiny.  Seeing a cow is not something accomplished as the terminal stage of a methodical process, however swift.  No task was accomplished, undertaken or envisaged.  I just saw a cow.  I did not so manage things or so organise my doings that at the last I saw a cow.  See a cow was, in an important way, the first thing that happened…

Now we must of course grant that the recognition on sight of the obvious cow is not the last move in a series of moves…But the non-occurrence of preliminaries does not entail the non-exercise of a technique.  We do not say that someone is skilful at something only when he frowns and hesitates over the doing of it; indeed, one of the signs that someone has achieved complete mastery of an art like signalling, pruning or long-division, is that he regularly performs perfectly the ordinary tasks in it without his wondering how to do it or preparing himself by any self-reminders, exhortation, exercises or other preliminaries.

Now we are all in the position of having achieved perfect mastery of the art of recognizing on sight the customary occupants of our customary environment–at least, when the light is good or fair, our health is normal, we are not dizzy or standing on our heads, looking through strange optical instruments and so on.  When all is plain sailing, no navigational problems are considered, nor do we try to make out what we are looking at when we get a fair view of a lonely cow in the sort of place where cows are among the things that we are not surprised to come across.  Of course we had once to learn how cows look at different distances, from different angles and in different lights, as well as where cows can be expected to be found, and it is just because that lesson has been learned and not forgotten that the cows is now obvious to us.  Its obviousness is the fact that the technique of recognizing it on sight has no longer to be exercised in a tentative way–and when we do have to exercise the technique in a tentative way, as when a cow confronts us in a thick fog, or in a hat shop, what we are looking at is for a moment or more not obviously a cow.  And, of course, the fact that it is ordinarily obvious that what we are looking at is a cow does not exclude the chance of its not being a cow at all.  It may be a goat, or a hole in the hedge looking like a cow.  Or there may be nothing that looks like a cow and I am just ‘seeing things’.  That such cases are exceptional is part of the meaning of such words as ‘see’. ‘perceive’, and so on, as well as of words like ‘obvious’.  If ‘I see a cow’ were not usually true, I could not fancy I saw a cow…