To understand this family of cases it will again be helpful to consider an analogous case drawn from facial expressions. There is a family of friendly facial expressions. Suppose we had asked, “What feature is it that characterizes a friendly face?” At first one might think that there are certain friendly traits which one might call friendly traits, each of which makes the face look friendly to a certain degree, and which when present in a large number constitute the friendly expression. This idea would seem to be borne out by our common speech, talk-
106.
ing of “friendly eyes”, “friendly mouth”, etc. But it is easy to see that the same eyes of which we say they make a face look friendly, do not look friendly, or even ˇlook unfriendly, with certain other wrinkles of the forehead, lines round the mouth, etc. Why then do we ever say that it is these eyes which look friendly? Isn't it wrong to say that they characterize the face as friendly, for if we say they do so “under certain circumstances” (these circumstances being the other features of the face) why did we single out the one feature from amongst the others? The answer is that in the wide family of friendly faces there is what one might call a main branch characterized by a certain kind of eyes, another by a certain kind of mouth, etc.; although in the large family of unfriendly faces we meet these same eyes when they don't mitigate the unfriendliness of the expression. ‒ ‒ There is further the fact that when we notice the friendly expression of a face, our attention, our gaze, is drawn to a particular feature in the face, the “friendly eyes” or the “friendly mouth”, etc., and that it does not rest on other features although these too are responsible for the friendly expression.