ments so quickly or with so little muscular effort. Public speaking would be very tedious if statesmen had to use the deaf-and-dumb language, and very exhausting if all words involved as much muscular effort as a shrug of the shoulders. I shall ignore all forms of language except speaking, hearing, writing, and reading, since the others are relatively unimportant and raise no special psychological problems.
A spoken word consists of a series of movements in the larynx and the mouth, combined with breath. Two closely similar series of such movements may be instances of the same word, though they may also not be, since two words with different meanings may sound alike; but two such series which are not closely similar cannot be instances of the same word. (I am confining myself to one language.) Thus a single spoken word, say "dog", is a certain set of closely similar series of bodily movements, the set having as many members as there are occasions when the word "dog" is pronounced. The degree of similarity required in order that the occurrence should be an instance of the word "dog" cannot be specified exactly. Some people say dawg", and this must certainly be admitted. A German might say "tok", and then we should begin to be doubtful. In marginal cases, we cannot be sure whether a word has been pronounced or not. A spoken word is a form of bodily behaviour without sharp boundaries, like jumping or hopping or running. Is a man running or walking? In a walking-race the umpire may have great difficulty in deciding. Similarly there may be cases where it cannot be decided whether a man has said "dog" or "dock". A spoken word is thus at once general and somewhat vague.
We usually take for granted the relation between a word spoken and a word heard. "Can you hear what I say?" we ask, and the person addressed says "yes". This is of course a delusion, a part of the naïve realism of our unreflective outlook on the world. We never hear what is said; we hear something having a complicated causal connection with what is said. There is first the purely physical process of sound-waves from the mouth of the speaker to
