CHAPTER VIEVENTS16. Apprehension of Events.16.1It is the purpose of this chapter to summarise the leading characteristics of our knowledge of nature as diversified into a complex of events.Perception is an awareness of events, or happenings, forming a partially discerned complex within the background of a simultaneous whole of nature. This awareness is definitely related to one event, or group of events, within the discerned complex. This event is called the percipient event. The simultaneity of the whole of nature comprising the discerned events is the special relation of that background of nature to the percipient event. This background is that complete event which is the whole of nature simultaneous with the percipient event, which is itself part of that whole. Such a complete whole of nature is called a 'duration.' A duration (in the sense in which henceforth the word will be used) is not an abstract stretch of time, and to that extent the term 'duration' is misleading. In perception the associated duration is apprehended as an essential element in the awareness, but it is not discriminated into all its parts and qualities. It is the complete subject matter for a discrimination which is only very partially performed.Thus the whole continuum of nature 'now-present' means one whole event (a duration), rendered definite by the limitation 'now-present' and extending over all events now-present. Namely, the various finite events now-present for an awareness are all parts of one associated duration which is a special type of event. A duration is in a sense unbounded; for it is, within certain limitations, all that there is. It has the property of completeness, limited by the condition 'now-present'; it is a temporal slab of nature.16.2This fact of nature as a present-whole is forced on our apprehension by the character of perception. Perceptual awareness is complex. There are the various types of sense-perception, and differences in extensity and in intensity. There are also differences in attention and in consequent clearness of awareness, shading off into a dim knowledge of events barely on the threshold of consciousness. Thus nature, as we know it, is a continuous stream of happening immediately present and partly dissected by our perceptual awareness into separated events with diverse qualities. Within this present stream the perceived is not sharply differentiated from the unperceived; there is always an indefinite 'beyond' of which we feel the presence although we do not discriminate the qualities of the parts. This knowledge of what is beyond discriminating perception is the basis of the scientific doctrine of externality. There is a present-whole of nature of which our detailed knowledge is dim and mediate and inferential, but capable of determination by its congruity with clear immediate perceptual facts.16.3The condition 'now-present' specifies a particular duration. It evidently refers to some relation; for 'now' is 'simultaneous with,' and 'present' is 'in the presence of' or 'presented to.' Thus 'now-present' refers to some relation between the duration and something else. This 'something else' is the event 'here-present,' which is the definite connecting link between individual experienced knowledge and self-sufficient nature. The essential existence of the event 'here-present' is the reason why perception is from within nature and is not an external survey. It is the 'percipient event.' The percipient event defines its associated duration, namely its corresponding 'all nature.'16.4The 'here' in 'here-present' also refers to the specific relation between the percipient event and its associated duration. It means 'here within the duration,' i.e. 'here within the present continuum of nature.' Thus the relation between an event 'here-present' and its associated duration embodies in some form the property of rest in the duration; for otherwise 'here' would be an equivocation. The relation in any concrete case may be complex, involving more than one meaning of 'here,' but the essential character of the relation is that as we (according to the method of extensive abstraction) properly diminish the extent of such an event, the property of 'rest in' the associated duration becomes more obvious. When an event has the property of being a percipient event unequivocally here within an associated duration, we shall say that it is 'cogredient' with the duration.16.5An event can be cogredient with only one duration. To have this relation to the duration it must be temporally present throughout the duration and exhibit one specific meaning of 'here.' But a duration can have many events cogredient with it. Namely any event, which is temporally present throughout that duration and in relation to an event here-present defines one specific meaning of 'there,' is an event 'there-present' which has the same relation of cogredience to that duration and (to that extent) is (so far) potentially an event 'here-present' in that duration for some possible act of apprehension. Thus cogredience is a condition for a percipient event yielding unequivocal meanings to 'here' and 'now.'The relation of cogredience presupposes that the duration extends over the event; but the two relations must not be confounded. In the first place a duration extends over events which are not temporally present throughout it, so that the specification of the duration would not be a complete answer to the question 'When?' as asked of the event. Secondly, the question 'Where?' which means 'Where in the duration?' may not be susceptible of the one definite answer 'There' which is only possible if cogredience holds. The question 'Whither?' which contemplates change in the 'there' of an event, definitely refers to events which are parts of a duration but are not cogredient with it. Cogredience is the relation of absolute position within a duration; we must remember that a duration is a slab of nature and not a mere abstract stretch of time. Cogredience is the relation which generates the consentient sets discussed inChapter IIIof Part I. The details of the deduction belong toPart III.16.6It is not necessary to assume that there is one event which is the system of all nature throughout all time. For scientific purposes the only unbounded events are durations and these are bounded in their temporal extension.17. The Constants of Externality.17.1The 'constants of externality' are those characteristics of a perceptual experience which it possesses when we assign to it the property of being an observation of the passage of external nature, namely when we apprehend it. A fact which possesses these characteristics, namely these constants of externality, is what we call an 'event.'A complete enumeration of these constants is not necessary for our purpose; we only need a survey of just those elements in the apprehension of externality from which the concepts of time, space and material arise. In this survey the attitude of mind to be avoided is exhibited in the questions, 'How, being in space, do we know it?' 'How, being in time, do we know it?' and 'How, having material, do we know of it?'Again we are not consideringà priorinecessities, nor are we appealing toà prioriprinciples in proof. We are merely investigating the characteristics which in experience we find belonging to perceived facts when we invest them with externality. The constants of externality are the conditions for nature, and determine the ultimate concepts which are presupposed in science.17.2In order to enter upon this investigation from the standpoint of habitual experience, consider the simplest general questions which can be asked of a percipient of some event in nature, 'Which?' 'What?' 'How?' 'When?' 'Where?' 'Whither?' These six questions fall into two sets. The first three invite specification of qualities and discrimination amid alternative entities; the remaining three refer to the spatio-temporal relation of a part to a whole within which in some sense the perceived part is located.They can be construed as referring to events or to objects. The former way of understanding them is evidently the more fundamental, for our awareness of nature is directly an awareness of events or happenings, which are the ultimate data of natural science. The conditions which determine the nature of events can only be furnished by other events, for there is nothing else in nature. A reference to objects is only a way of specifying the character of an event. It is an error to conceive of objects as causing an event, except in the sense that the characters of antecedent events furnish conditions which determine the natures of subsequent events.17.3The ultimate nature of events has been blurred by the confusion which seems to be introduced by its acknowledgment. Events appear as indefinite entities without clear demarcations and with mutual relations of baffling complexity. They seem, so to speak, deficient in thinghood. A lump of matter or a charge of electricity in a position at an instant, retaining its self-identity in other positions at succeeding instants, seems a simple clue for the unravelling of the maze. This may be unreservedly granted; but our purpose is to exhibit this conception of spatio-temporal material in its true relation to events. When this has been effected, the mechanical rigidity (so to speak) of the traditional views of time, space and material is thereby lost, and the way is opened for such readjustments as the advance of experimental knowledge may suggest.17.4The six questions of17.2immediately reveal that what is ultimate in nature is a set of determinate things, each with its own relations to other things of the set. To say this is a truism, for thought and judgment are impossible without determinate subjects. But the reluctance to abandon a vague indetermination of events has been an implicit reason for the refusal to consider them as the ultimate natural entities.This demarcation of events is the first difficulty which arises in applying rational thought to experience. In perception no event exhibits definite spatio-temporal limits. A continuity of transition is essential. The definition of an event by assignment of demarcations is an arbitrary act of thought corresponding to no perceptual experience. Thus it is a basal assumption, essential for ratiocination relating to perceptual experience, that there are definite entities which are events; though in practice our experience does not enable us to identify any such subject of thought, as discriminated from analogous subjects slightly more or slightly less.This assumption must not be construed either as asserting an atomic structure of events, or as a denial of overlapping events. It merely asserts the ideal possibility of perfect definiteness as to what does or does not belong to an event which is the subject of thought, though such definiteness cannot be achieved in human knowledge. It is the claim which is implicit in every advance towards exact observation, namely that there is something definite to be known. The assumption is the first constant of externality, namely the belief that what has been apprehended as a continuum, is a potentially definite complex of entities for knowledge. The assumption is closely allied with the conception of nature as 'given.' This conception is the thought of an event as a thing which 'happened' apart from all theory and as a fact self-sufficient for a knowledge discriminating it alone.18. Extension.18.1The second constant of externality is the relation of extension which holds between events. An eventmay 'extend over' an event, i.e. in other wordsmay be part of. The concepts of time and of space in the main, though not entirely, arise from the empirically determined properties of this relation of extension. It is evident from the universal and uniform application of the spatio-temporal concepts that they must arise from the utilisation of the simplest characteristics without which no datum of knowledge would be recognised as an event belonging to the order of nature. Extension is a relation of this type. It is a property so simple that we hardly recognise it as such—it of course is so. Thus the event which is the passage of the car is part of the whole life of the street. Also the passage of a wheel is part of the event which is the passage of the car. Similarly the event which is the continued existence of the house extends over the event which is the continued existence of a brick of the house, and the existence of the house during one day extends over its existence during one specified second of that day.18.2Every element of space or of time (as conceived in science) is an abstract entity formed out of this relation of extension (in association at certain stages with the relation of cogredience) by means of a determinate logical procedure (the method of extensive abstraction). The importance of this procedure depends on certain properties of extension which are laws of nature depending on empirical verification. There is, so far as I know, no reason why they should be so, except that they are. These laws will be stated in the succeeding parts so far as is necessary to exemplify the definitions which are there given and to show that these definitions really indicate the familiar spatial and temporal entities which are utilised by science in precise and determinate ways. Many of the laws can be logically proved when the rest are assumed. But the proofs will not be given here, as our aim is to investigate the structure of the ideas which we apply to nature and the fundamental laws of nature which determine their importance, and not to investigate the deductive science which issues from them.18.3The various elements of time and space are formed by the repeated applications of the method of extensive abstraction. It is a method which in its sphere achieves the same object as does the differential calculus in the region of numerical calculation, namely it converts a process of approximation into an instrument of exact thought. The method is merely the systematisation of the instinctive procedure of habitual experience. The approximate procedure of ordinary life is to seek simplicity of relations among events by the consideration of events sufficiently restricted in extension both as to space and as to time; the events are then 'small enough.' The procedure of the method of extensive abstraction is to formulate the law by which the approximation is achieved and can be indefinitely continued. The complete series is then defined and we have a 'route of approximation.' These routes of approximation according to the variation of the details of their formation are the points of instantaneous space (here called 'event-particles'), linear segments (straight or curved) between event-particles (here called 'routes'), the moments of time (each of which is all instantaneous nature), and the volumes incident in moments. Such elements are the exactly determined concepts on which the whole fabric of science rests.18.4The parts of an event are the set of events (excluding itself) which the given event extends over. It is a mistake to conceive an event as the mere logical sum of its parts. In the first place if we do so, we are necessarily driven back to conceive of more fundamental entities, not events, which would not have the mere abstract logical character which (on this supposition) events would then have. Secondly, the parts of an event are not merely one set of non-overlapping events exhausting the given event. They are the whole complex of events contained in that event; for example, ifbe the given event, andextends over andover, thenextends overand bothandare parts of. Thus an event has its own substantial unity of being which is not an abstract derivative from logical construction. The physical fact of the concrete unity of an event is the foundation of the continuity of nature from which are derived the precise laws of the mathematical continuity of time and space. Not any two events are in combination just one event, though there will be other events of which both are parts. We recur to this point in Part III,art. 29, when considering the junction of events.19. Absolute Position.19.1The third constant of externality is the fact (already explained) that an event as apprehended is related to a complete whole of nature which extends over it and is the duration associated with the percipient event of that perception.19.2The fourth constant of externality is the reference (already explained) of the apprehended event to the percipient event which (when sufficiently restricted in its temporal extension) has a definite station within the associated duration.19.3The fifth constant is the above-mentioned fact of the definite station of a percipient event within its duration. Namely, when the specious present is properly limited, there is a definite univocal meaning to the relation 'here within the duration' of the percipient event to the duration.19.4Thus the third, fourth, and fifth constants of externality convey its very essence, and without them our perceptual experience appears as a disconnected dream. They embody the reference of an event to a definite—an absolute—spatio-temporal position within a definite whole of nature, which whole is defined and limited by the actual circumstances of the perception. This position, or station, within such a whole is presupposed in the questions, 'When?' 'Where?' 'Whither?'20. The Community of Nature.20.1One other constant of externality is required in scientific thought. We will call it the association of events with a 'community of nature.' This sixth constant arises from the fragmentary nature of perceptual knowledge. There are breaks in individual perception, and there are distinct streams of perception corresponding to diverse percipients. For example, as one percipient awakes daily to a fresh perceptual stream, he apprehends the same external nature which can be comprised in one large duration extending over all his days. Again the same nature and the same events are apprehended by diverse percipients; at least, what they apprehend is as though it were the same for all.20.2Thus we distinguish between the qualities of events as in individual perception—namely, the sense-data of individuals—and the objective qualities of the actual events within the common nature which is the datum for apprehension. In this assumption of a nature common for all percipients, the immediate knowledge of the individual percipient is entirely his perceptual awareness derived from the bodily event 'now-present here.' But this event occurs as related to the events of antecedent or concurrent nature. Accordingly he is aware of these events as related to his bodily event 'now-present here'; but his knowledge is thus mediate and relative—namely, he only knows other events through the medium of his body and as determined by relations to it. The event here-now, comprising in general the bodily events, is the immediate event conditioning awareness.20.3The form that this awareness of nature takes is an awareness of sense-objects now-present, namely qualities situated in the events within the duration associated with the percipient event. Thus the immediate awareness qualifies the events of the specious present. Thus the common nature which is the object of scientific research has to be constructed as an interpretation. This interpretation is liable to error, and involves adjustments. This question is further considered in the next chapter and inPart IV.21. Characters of Events.21.1The characters of events arbitrarily marked out in nature are of baffling complexity. There are two ways of obtaining events of a certain simplicity. In the first place we may consider events cogredient with our present duration. This is in fact to fix attention on a given position in space and to consider what is now going on within it. The spatial relations will be simplified, but (unless we are lucky) the other characters will be very complex. The second method is to consider events whose time-parts show a certain permanence of character. This is in fact to follow the fortunes of objects, and may be termed the natural mode of discriminating the continuous stream of external nature into events. The importance of this mode of discrimination could only be ascertained by experience.21.2There is one essential event which each percipient discriminates, namely that event of which each part, contained within each successive duration that assumes for him the character of the duration now-present, correspondingly assumes for him the character of the event here-present. This event is the life of that organism which links the percipient's awareness to external nature.21.3The thesis of this chapter can finally be summarised as follows: There is a structure of events and this structure provides the framework of the externality of nature within which objects are located. Any percept which does not find its position within this structure is not for us a perceptofexternal nature, though it may find its explanationfromexternal events as being derived from them. The character of the structure receives its exposition from the quantitative and qualitative relations of space and time. Space and time are abstractions expressive of certain qualities of the structure. This space-time abstraction is not unique, so that many space-time abstractions are possible, each with its own specific relation to nature. The particular space-time abstraction proper to a particular observant mind depends on the character of the percipient event which is the medium relating that mind to the whole of nature. In a space-time abstraction, time expresses certain qualities of the passage of nature. This passage has also been called the creative advance of nature. But this passage is not adequately expressed by any one time-system. The whole set of time-systems derived from the whole set of space-time abstractions expresses the totality of those properties of the creative advance which are capable of being rendered explicit in thought. Thus no single duration can be completely concrete in the sense of representing a possible whole of all nature without omission. For a duration is essentially related to one space-time system and thus omits those aspects of the passage which find expression in other space-time systems. Accordingly there can be no duration whose bounding moments are the first and last moments of creation.Objects are entities recognised as appertaining to events ; they are the recognita amid events. Events are named after the objects involved in them and according to how they are involved.
16. Apprehension of Events.16.1It is the purpose of this chapter to summarise the leading characteristics of our knowledge of nature as diversified into a complex of events.
Perception is an awareness of events, or happenings, forming a partially discerned complex within the background of a simultaneous whole of nature. This awareness is definitely related to one event, or group of events, within the discerned complex. This event is called the percipient event. The simultaneity of the whole of nature comprising the discerned events is the special relation of that background of nature to the percipient event. This background is that complete event which is the whole of nature simultaneous with the percipient event, which is itself part of that whole. Such a complete whole of nature is called a 'duration.' A duration (in the sense in which henceforth the word will be used) is not an abstract stretch of time, and to that extent the term 'duration' is misleading. In perception the associated duration is apprehended as an essential element in the awareness, but it is not discriminated into all its parts and qualities. It is the complete subject matter for a discrimination which is only very partially performed.
Thus the whole continuum of nature 'now-present' means one whole event (a duration), rendered definite by the limitation 'now-present' and extending over all events now-present. Namely, the various finite events now-present for an awareness are all parts of one associated duration which is a special type of event. A duration is in a sense unbounded; for it is, within certain limitations, all that there is. It has the property of completeness, limited by the condition 'now-present'; it is a temporal slab of nature.
16.2This fact of nature as a present-whole is forced on our apprehension by the character of perception. Perceptual awareness is complex. There are the various types of sense-perception, and differences in extensity and in intensity. There are also differences in attention and in consequent clearness of awareness, shading off into a dim knowledge of events barely on the threshold of consciousness. Thus nature, as we know it, is a continuous stream of happening immediately present and partly dissected by our perceptual awareness into separated events with diverse qualities. Within this present stream the perceived is not sharply differentiated from the unperceived; there is always an indefinite 'beyond' of which we feel the presence although we do not discriminate the qualities of the parts. This knowledge of what is beyond discriminating perception is the basis of the scientific doctrine of externality. There is a present-whole of nature of which our detailed knowledge is dim and mediate and inferential, but capable of determination by its congruity with clear immediate perceptual facts.
16.3The condition 'now-present' specifies a particular duration. It evidently refers to some relation; for 'now' is 'simultaneous with,' and 'present' is 'in the presence of' or 'presented to.' Thus 'now-present' refers to some relation between the duration and something else. This 'something else' is the event 'here-present,' which is the definite connecting link between individual experienced knowledge and self-sufficient nature. The essential existence of the event 'here-present' is the reason why perception is from within nature and is not an external survey. It is the 'percipient event.' The percipient event defines its associated duration, namely its corresponding 'all nature.'
16.4The 'here' in 'here-present' also refers to the specific relation between the percipient event and its associated duration. It means 'here within the duration,' i.e. 'here within the present continuum of nature.' Thus the relation between an event 'here-present' and its associated duration embodies in some form the property of rest in the duration; for otherwise 'here' would be an equivocation. The relation in any concrete case may be complex, involving more than one meaning of 'here,' but the essential character of the relation is that as we (according to the method of extensive abstraction) properly diminish the extent of such an event, the property of 'rest in' the associated duration becomes more obvious. When an event has the property of being a percipient event unequivocally here within an associated duration, we shall say that it is 'cogredient' with the duration.
16.5An event can be cogredient with only one duration. To have this relation to the duration it must be temporally present throughout the duration and exhibit one specific meaning of 'here.' But a duration can have many events cogredient with it. Namely any event, which is temporally present throughout that duration and in relation to an event here-present defines one specific meaning of 'there,' is an event 'there-present' which has the same relation of cogredience to that duration and (to that extent) is (so far) potentially an event 'here-present' in that duration for some possible act of apprehension. Thus cogredience is a condition for a percipient event yielding unequivocal meanings to 'here' and 'now.'
The relation of cogredience presupposes that the duration extends over the event; but the two relations must not be confounded. In the first place a duration extends over events which are not temporally present throughout it, so that the specification of the duration would not be a complete answer to the question 'When?' as asked of the event. Secondly, the question 'Where?' which means 'Where in the duration?' may not be susceptible of the one definite answer 'There' which is only possible if cogredience holds. The question 'Whither?' which contemplates change in the 'there' of an event, definitely refers to events which are parts of a duration but are not cogredient with it. Cogredience is the relation of absolute position within a duration; we must remember that a duration is a slab of nature and not a mere abstract stretch of time. Cogredience is the relation which generates the consentient sets discussed inChapter IIIof Part I. The details of the deduction belong toPart III.
16.6It is not necessary to assume that there is one event which is the system of all nature throughout all time. For scientific purposes the only unbounded events are durations and these are bounded in their temporal extension.
17. The Constants of Externality.17.1The 'constants of externality' are those characteristics of a perceptual experience which it possesses when we assign to it the property of being an observation of the passage of external nature, namely when we apprehend it. A fact which possesses these characteristics, namely these constants of externality, is what we call an 'event.'
A complete enumeration of these constants is not necessary for our purpose; we only need a survey of just those elements in the apprehension of externality from which the concepts of time, space and material arise. In this survey the attitude of mind to be avoided is exhibited in the questions, 'How, being in space, do we know it?' 'How, being in time, do we know it?' and 'How, having material, do we know of it?'
Again we are not consideringà priorinecessities, nor are we appealing toà prioriprinciples in proof. We are merely investigating the characteristics which in experience we find belonging to perceived facts when we invest them with externality. The constants of externality are the conditions for nature, and determine the ultimate concepts which are presupposed in science.
17.2In order to enter upon this investigation from the standpoint of habitual experience, consider the simplest general questions which can be asked of a percipient of some event in nature, 'Which?' 'What?' 'How?' 'When?' 'Where?' 'Whither?' These six questions fall into two sets. The first three invite specification of qualities and discrimination amid alternative entities; the remaining three refer to the spatio-temporal relation of a part to a whole within which in some sense the perceived part is located.
They can be construed as referring to events or to objects. The former way of understanding them is evidently the more fundamental, for our awareness of nature is directly an awareness of events or happenings, which are the ultimate data of natural science. The conditions which determine the nature of events can only be furnished by other events, for there is nothing else in nature. A reference to objects is only a way of specifying the character of an event. It is an error to conceive of objects as causing an event, except in the sense that the characters of antecedent events furnish conditions which determine the natures of subsequent events.
17.3The ultimate nature of events has been blurred by the confusion which seems to be introduced by its acknowledgment. Events appear as indefinite entities without clear demarcations and with mutual relations of baffling complexity. They seem, so to speak, deficient in thinghood. A lump of matter or a charge of electricity in a position at an instant, retaining its self-identity in other positions at succeeding instants, seems a simple clue for the unravelling of the maze. This may be unreservedly granted; but our purpose is to exhibit this conception of spatio-temporal material in its true relation to events. When this has been effected, the mechanical rigidity (so to speak) of the traditional views of time, space and material is thereby lost, and the way is opened for such readjustments as the advance of experimental knowledge may suggest.
17.4The six questions of17.2immediately reveal that what is ultimate in nature is a set of determinate things, each with its own relations to other things of the set. To say this is a truism, for thought and judgment are impossible without determinate subjects. But the reluctance to abandon a vague indetermination of events has been an implicit reason for the refusal to consider them as the ultimate natural entities.
This demarcation of events is the first difficulty which arises in applying rational thought to experience. In perception no event exhibits definite spatio-temporal limits. A continuity of transition is essential. The definition of an event by assignment of demarcations is an arbitrary act of thought corresponding to no perceptual experience. Thus it is a basal assumption, essential for ratiocination relating to perceptual experience, that there are definite entities which are events; though in practice our experience does not enable us to identify any such subject of thought, as discriminated from analogous subjects slightly more or slightly less.
This assumption must not be construed either as asserting an atomic structure of events, or as a denial of overlapping events. It merely asserts the ideal possibility of perfect definiteness as to what does or does not belong to an event which is the subject of thought, though such definiteness cannot be achieved in human knowledge. It is the claim which is implicit in every advance towards exact observation, namely that there is something definite to be known. The assumption is the first constant of externality, namely the belief that what has been apprehended as a continuum, is a potentially definite complex of entities for knowledge. The assumption is closely allied with the conception of nature as 'given.' This conception is the thought of an event as a thing which 'happened' apart from all theory and as a fact self-sufficient for a knowledge discriminating it alone.
18. Extension.18.1The second constant of externality is the relation of extension which holds between events. An eventmay 'extend over' an event, i.e. in other wordsmay be part of. The concepts of time and of space in the main, though not entirely, arise from the empirically determined properties of this relation of extension. It is evident from the universal and uniform application of the spatio-temporal concepts that they must arise from the utilisation of the simplest characteristics without which no datum of knowledge would be recognised as an event belonging to the order of nature. Extension is a relation of this type. It is a property so simple that we hardly recognise it as such—it of course is so. Thus the event which is the passage of the car is part of the whole life of the street. Also the passage of a wheel is part of the event which is the passage of the car. Similarly the event which is the continued existence of the house extends over the event which is the continued existence of a brick of the house, and the existence of the house during one day extends over its existence during one specified second of that day.
18.2Every element of space or of time (as conceived in science) is an abstract entity formed out of this relation of extension (in association at certain stages with the relation of cogredience) by means of a determinate logical procedure (the method of extensive abstraction). The importance of this procedure depends on certain properties of extension which are laws of nature depending on empirical verification. There is, so far as I know, no reason why they should be so, except that they are. These laws will be stated in the succeeding parts so far as is necessary to exemplify the definitions which are there given and to show that these definitions really indicate the familiar spatial and temporal entities which are utilised by science in precise and determinate ways. Many of the laws can be logically proved when the rest are assumed. But the proofs will not be given here, as our aim is to investigate the structure of the ideas which we apply to nature and the fundamental laws of nature which determine their importance, and not to investigate the deductive science which issues from them.
18.3The various elements of time and space are formed by the repeated applications of the method of extensive abstraction. It is a method which in its sphere achieves the same object as does the differential calculus in the region of numerical calculation, namely it converts a process of approximation into an instrument of exact thought. The method is merely the systematisation of the instinctive procedure of habitual experience. The approximate procedure of ordinary life is to seek simplicity of relations among events by the consideration of events sufficiently restricted in extension both as to space and as to time; the events are then 'small enough.' The procedure of the method of extensive abstraction is to formulate the law by which the approximation is achieved and can be indefinitely continued. The complete series is then defined and we have a 'route of approximation.' These routes of approximation according to the variation of the details of their formation are the points of instantaneous space (here called 'event-particles'), linear segments (straight or curved) between event-particles (here called 'routes'), the moments of time (each of which is all instantaneous nature), and the volumes incident in moments. Such elements are the exactly determined concepts on which the whole fabric of science rests.
18.4The parts of an event are the set of events (excluding itself) which the given event extends over. It is a mistake to conceive an event as the mere logical sum of its parts. In the first place if we do so, we are necessarily driven back to conceive of more fundamental entities, not events, which would not have the mere abstract logical character which (on this supposition) events would then have. Secondly, the parts of an event are not merely one set of non-overlapping events exhausting the given event. They are the whole complex of events contained in that event; for example, ifbe the given event, andextends over andover, thenextends overand bothandare parts of. Thus an event has its own substantial unity of being which is not an abstract derivative from logical construction. The physical fact of the concrete unity of an event is the foundation of the continuity of nature from which are derived the precise laws of the mathematical continuity of time and space. Not any two events are in combination just one event, though there will be other events of which both are parts. We recur to this point in Part III,art. 29, when considering the junction of events.
19. Absolute Position.19.1The third constant of externality is the fact (already explained) that an event as apprehended is related to a complete whole of nature which extends over it and is the duration associated with the percipient event of that perception.
19.2The fourth constant of externality is the reference (already explained) of the apprehended event to the percipient event which (when sufficiently restricted in its temporal extension) has a definite station within the associated duration.
19.3The fifth constant is the above-mentioned fact of the definite station of a percipient event within its duration. Namely, when the specious present is properly limited, there is a definite univocal meaning to the relation 'here within the duration' of the percipient event to the duration.
19.4Thus the third, fourth, and fifth constants of externality convey its very essence, and without them our perceptual experience appears as a disconnected dream. They embody the reference of an event to a definite—an absolute—spatio-temporal position within a definite whole of nature, which whole is defined and limited by the actual circumstances of the perception. This position, or station, within such a whole is presupposed in the questions, 'When?' 'Where?' 'Whither?'
20. The Community of Nature.20.1One other constant of externality is required in scientific thought. We will call it the association of events with a 'community of nature.' This sixth constant arises from the fragmentary nature of perceptual knowledge. There are breaks in individual perception, and there are distinct streams of perception corresponding to diverse percipients. For example, as one percipient awakes daily to a fresh perceptual stream, he apprehends the same external nature which can be comprised in one large duration extending over all his days. Again the same nature and the same events are apprehended by diverse percipients; at least, what they apprehend is as though it were the same for all.
20.2Thus we distinguish between the qualities of events as in individual perception—namely, the sense-data of individuals—and the objective qualities of the actual events within the common nature which is the datum for apprehension. In this assumption of a nature common for all percipients, the immediate knowledge of the individual percipient is entirely his perceptual awareness derived from the bodily event 'now-present here.' But this event occurs as related to the events of antecedent or concurrent nature. Accordingly he is aware of these events as related to his bodily event 'now-present here'; but his knowledge is thus mediate and relative—namely, he only knows other events through the medium of his body and as determined by relations to it. The event here-now, comprising in general the bodily events, is the immediate event conditioning awareness.
20.3The form that this awareness of nature takes is an awareness of sense-objects now-present, namely qualities situated in the events within the duration associated with the percipient event. Thus the immediate awareness qualifies the events of the specious present. Thus the common nature which is the object of scientific research has to be constructed as an interpretation. This interpretation is liable to error, and involves adjustments. This question is further considered in the next chapter and inPart IV.
21. Characters of Events.21.1The characters of events arbitrarily marked out in nature are of baffling complexity. There are two ways of obtaining events of a certain simplicity. In the first place we may consider events cogredient with our present duration. This is in fact to fix attention on a given position in space and to consider what is now going on within it. The spatial relations will be simplified, but (unless we are lucky) the other characters will be very complex. The second method is to consider events whose time-parts show a certain permanence of character. This is in fact to follow the fortunes of objects, and may be termed the natural mode of discriminating the continuous stream of external nature into events. The importance of this mode of discrimination could only be ascertained by experience.
21.2There is one essential event which each percipient discriminates, namely that event of which each part, contained within each successive duration that assumes for him the character of the duration now-present, correspondingly assumes for him the character of the event here-present. This event is the life of that organism which links the percipient's awareness to external nature.
21.3The thesis of this chapter can finally be summarised as follows: There is a structure of events and this structure provides the framework of the externality of nature within which objects are located. Any percept which does not find its position within this structure is not for us a perceptofexternal nature, though it may find its explanationfromexternal events as being derived from them. The character of the structure receives its exposition from the quantitative and qualitative relations of space and time. Space and time are abstractions expressive of certain qualities of the structure. This space-time abstraction is not unique, so that many space-time abstractions are possible, each with its own specific relation to nature. The particular space-time abstraction proper to a particular observant mind depends on the character of the percipient event which is the medium relating that mind to the whole of nature. In a space-time abstraction, time expresses certain qualities of the passage of nature. This passage has also been called the creative advance of nature. But this passage is not adequately expressed by any one time-system. The whole set of time-systems derived from the whole set of space-time abstractions expresses the totality of those properties of the creative advance which are capable of being rendered explicit in thought. Thus no single duration can be completely concrete in the sense of representing a possible whole of all nature without omission. For a duration is essentially related to one space-time system and thus omits those aspects of the passage which find expression in other space-time systems. Accordingly there can be no duration whose bounding moments are the first and last moments of creation.
Objects are entities recognised as appertaining to events ; they are the recognita amid events. Events are named after the objects involved in them and according to how they are involved.