r and later parts, as between the earlier and later parts
of Jones. Thus an instance of walking differs from an instance of man
solely by the fact that it has a shorter life. There is a notion that an
instance of walking, as compared with Jones, is unsubstantial, but this
seems to be a mistake. We think that Jones walks, and that there could
not be any walking unless there were somebody like Jones to perform
the walking. But it is equally true that there could be no Jones unless
there were something like walking for him to do. The notion that actions
are performed by an agent is liable to the same kind of criticism as
the notion that thinking needs a subject or ego, which we rejected in
Lecture I. To say that it is Jones who is walking is merely to say that
the walking in question is part of the whole series of occurrences which
is Jones. There is no LOGICAL impossibility in walking occurring as an
isolated phenomenon, not forming part of any such series as we call a
"person."

We may therefore class with "eating," "walking," "speaking" words
such as "rain," "sunrise," "lightning," which do not denote what would
commonly be called actions. These words illustrate, incidentally, how
little we can trust to the grammatical distinction of parts of speech,
since the substantive "rain" and the verb "to rain" denote precisely the
same class of meteorological occurrences. The distinction between the
class of objects denoted by such a word and the class of objects denoted
by a general name such as "man," "vegetable," or "planet," is that the
sort of object which is an instance of (say) "lightning" is much simpler
than (say) an individual man. (I am speaking of lightning as a sensible
phenomenon, not as it is described in physics.) The distinction is one
of degree, not of kind. But there is, from the point of view of ordinary
thought, a great difference between a process which, like a flash of
lightning, can be wholly comprised within one specious present and a
process which, like the life of a man, has to be pieced together by
observation and memory and the apprehension of causal connections.
We may say broadly, therefore, that a word of the kind we have been
discussing denotes a set of similar occurrences, each (as a rule) much
more brief and less complex than a person or thing. Words themselves, as
we have seen, are sets of similar occurrences of this kind. Thus there
is more logical affinity between a word and what it means in