discerned entities. Still further, this separation of the ideas of space and time has merely been adopted for the sake of gaining simplicity of exposition by conformity to current language. What we discern is the specific character of a place through a period of time. This is what I mean by an 'event.* We discern some specific character of an event. But in discerning an event we are also aware of its significance as a relatum in the struc- ture of events. This structure of events is the complex of events as related by the two relations of extension and cogredience. The most simple expression of the proper- ties of this structure are to be found in our spatial and temporal relations. A discerned event is known as related in this structure to other events whose specific characters are otherwise not disclosed in that immediate awareness except so far as that they are relata within the structure. The disclosure in sense-awareness of the structure of events classifies events into those which are discerned in respect to some further individual character and those which are not otherwise disclosed except as elements of the structure. These signified events must include events in the remote past as well as events in the future. We are aware of these as the far oflF periods of unbounded time. But there is another classification of events which is also inherent in sense-awareness. These are the events which share the immediacy of the im- mediately present discerned events. These are the events whose characters together with those of the discerned events comprise all nature present for discernment. They form the complete general fact which is all nature now present as disclosed in that sense-awareness. It is in this second classification of events that the differentia- tion of space from time takes its origin. The germ of
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space is to be found in the mutual relations of events
within the immediate general fact which is all nature
now discernible, namely within the one event which is
the totality of present nature. The relations of other
events to this totality of nature form the texture of time.
The unity of this general present fact is expressed by the concept of simultaneity. The general fact is the whole simultaneous occurrence of nature which is now for sense-awareness. This general fact is what I have called the discernible. But in future I will call it a 'duration,' meaning thereby a certain whole of nature which is limited only by the property of being a simul- taneity. Further in obedience to the principle of com- prising within nature the whole terminus of sense-aware- ness, simultaneity must not be conceived as an irrelevant mental concept imposed upon nature. Our sense- awareness posits for immediate discernment a certain whole, here called a 'duration'; thus a duration is a definite natural entity. A duration is discriminated as a complex of partial events, and the natural entities which are components of this complex are thereby said to be 'simultaneous with this duration.' Also in a derivative sense they are simultaneous with each other in respect to this duration. Thus simultaneity is a definite natural relation. The word ' duration ' is perhaps unfortunate in so far as it suggests a mere abstract stretch of time. This is not what I mean. A duration is a concrete slab of nature limited by simultaneity which is an essential factor disclosed in sense-awareness.
Nature is a process. As in the case of everything
directly exhibited in sense-awareness, there can be no
explanation of this characteristic of nature. All that
can be done is to use language which may speculatively
54 THE CONCEPT OF NATURE [ch.
demonstrate it, and also to express the relation of this factor in nature to other factors.
It is an exhibition of the process of nature that each duration happens and passes. The process of nature can also be termed the passage of nature. I definitely refrain at this stage from using the word 'time,' since the measurable time of science and of civilised life generally merely exhibits some aspects of the more fundamental fact of the passage of nature. I believe that in this doctrine I am in full accord with Bergson, though he uses 'time' for the fundamental fact which I call the 'passage of nature.' Also the passage of nature is ex- hibited equally in spatial transition as well as in temporal transition. It is in virtue of its passage that nature is always moving on. It is involved in the meaning of this property of ' moving on ' that not only is any act of sense- awareness just that act and no other, but the terminus of each act is also unique and is the terminus of no other act. Sense-awareness seizes its only chance and presents for knowledge something which is for it alone.
There are two senses in which the terminus of sense-
awareness is unique. It is unique for the sense-aware-
ness of an individual mind and it is unique for the
sense-awareness of all minds which are operating under
natural conditions. There is an important distinction
between the two cases, (i) For one mind not only is the
discerned component of the general fact exhibited in
any act of sense-awareness distinct from the discerned
component of the general fact exhibited in any other
act of sense-awareness of that mind, but the two corre-
sponding durations which are respectively related by
simultaneity to the two discerned components are
necessarily distinct. This is an exhibition of the temporal
in] TIME
passage of nature ; namely, one duration has passed into the other. Thus not only is the passage of nature an essential character of nature in its rSle of the terminus of sense-awareness, but it is also essential for sense- awareness in itself. It is this truth which makes time appear to extend beyond nature. But what extends beyond nature to mind is not the serial and measurable time, which exhibits merely the character of passage in nature, but the quality of passage itself which is in no way measurable except so far as it obtains in nature. That is to say, 'passage' is not measurable except as it occurs in nature in connexion with extension. In passage we reach a connexion of nature with the ultimate metaphysical reality. The quality of passage in dura- tions is a particular exhibition in nature of a quality which extends beyond nature. For example passage is a quality not only of nature, which is the thing known, but also of sense-awareness which is the procedure of knowing. Durations have all the reality that nature has, though what that may be we need not now determine. The measurableness of time is derivative from the properties of durations. So also is the serial character of time. We shall find that there are in nature competing serial time-systems derived from different families of durations. These are a peculiarity of the character of passage as it is found in nature. This character has the reality of nature, but we must not necessarily transfer natural time to extra-natural entities, (ii) For two minds, the discerned components of the general facts exhibited in their respective acts of sense-awareness must be different. For each mind, in its awareness of nature is aware of a certain complex of related natural entities in their relations to the living body as a focus. But the
56 . THE CONCEPT OF NATURE [CH.
associated durations may be identical. Here we are
touching on that character of the passage nature which
issues in the spatial relations of simultaneous bodies.
This possible identity of the durations in the case of
the sense-awareness of distinct minds is what binds
into one nature the private experiences of sentient
beings. We are here considering the spatial side of the
passage of nature. Passage in this aspect of it also seems
to extend beyond nature to mind.
It is important to distinguish simultaneity from in-
stantaneousness. I lay no stress on the mere current
usage of the two terms. There are two concepts which
I want to distinguish, and one I call simultaneity and
the other instantaneousness. I hope that the words are
judiciously chosen; but it really does not matter so
long as I succeed in explaining my meaning. Simul-
taneity is the property of a group of natural elements
which in some sense are components of a duration.
A duration can be all nature present as the immediate
fact posited by sense-awareness. A duration retains
within itself the passage of nature. There are within it
antecedents and consequents which are also durations
which may be the complete specious presents of quicker
consciousnesses. In other words a duration retains
temporal thickness. Any concept of all nature as imme-
diately known is always a concept of some duration
though it may be enlarged in its temporal thickness
beyond the possible specious present of any being known
to us as existing within nature. Thus simultaneity is an
ultimate factor in nature, immediate for sense-awareness.
Instantaneousness is a complex logical concept of a
procedure in thought by which constructed logical
entities are produced for the sake of the simple ex-
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pression in thought of properties of nature. Instan- ,y taneousness is the concept of all nature at an instant, where an instant is conceived as deprived of all tem- poral extension. For example we conceive of the dis- tribution of matter in space at an instant. This is a very useful concept in science especially in applied mathe- matics ; but it is a very complex idea so far as concerns its connexions with the immediate facts of sense- awareness. There is no such thing as nature at an instant posited by sense-awareness. What sense-awareness delivers over for knowledge is nature through a period. Accordingly nature at an instant, since it is not itself a natural entity, must be defined in terms of genuine ' natural entities. Unless we do so, our science, which i employs the concept of instantaneous nature, must abandon all claim to be founded upon observation.
y[_will use the term ' moment ' to mean ' all nature at an instant.' A moment, in the sense in which the term is here used, has no temporal extension, and is in this re- spect to be contrasted with a duration which has such extension. What is directly yielded to our knowledge by sense-awareness is a duration. Accordingly we have now to explain how moments are derived from durations, and also to explain the purpose served by their introduction, i
A moment is a limit to which we approach as we i j
confine attention to durations of minimum extension.
Natural relations among the ingredients of a duration
gain in complexity as we consider durations of increasing
temporal extension. Accordingly there is an approach
to ideal simplicity as we approach an ideal diminution
of extension.
The word 'limit' has a precise signification in the logic of number and even in the logic of non-numerical
58 THE CONCEPT OF NATURE [ch.
one-dimensional series. As used here it is so far a mere
metaphor, and it is necessary to explain directly the
concept which it is meant to indicate.
Durations can have the two-termed relational pro- perty of extending one over the other. Thus the duration which is all nature during a certain minute extends over the duration which is all nature during the 30th second of that minute. This relation of 'extending over' — 'extension' as I shall call it — is a fundamental natural relation whose field comprises more than durations. It is a relation which two limited events can have to each other. Furthermore as holding between durations the relation appears to refer to the purely temporal ex- tension. I shall however maintain that the same relation of extension lies at the base both of temporal and spatial extension. This discussion can be postponed; and for the present we are simply concerned with the relation of extension as it occurs in its temporal aspect for the limited field of durations.
The concept of extension exhibits in thought one side of the ultimate passage of nature. This relation holds because of the special character which passage assumes in nature ; it is the relation which in the case of durations expresses the properties of 'passing over.' Thus the duration which was one definite minute passed over the duration which was its 30th second. The duration of the 30th second was part of the duration of the minute. I shall use the terms ' whole 'and * part ' exclusively in this sense, that the ' part ' is an event which is extended over by the other event which is the ' whole.' Thus in my nomencla- ture ' whole ' and ' part ' refer exclusively to this funda- mental relation of extension; and accordingly in this technical usage only events can be either wholes or parts.
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