iS6 THE CONCEPT OF NATURE [ch.
sense-object are to be found in the percipient event.
Namely we are to look for them in the investigations
of medical psychologists. The ingression into nature of
the delusive sense-object is conditioned by the adapta-
tion of bodily events to the more normal occurrence, -
which is the ingression of the physical object.
A perceptual object is a physical object when (i) its situation is an active conditioning event for the in- gression of any of its component sense-objects, and (ii) the same event can be the situation of the perceptual object for an indefinite number of possible percipient events. Physical objects are the ordinary objects which we perceive when our senses are not cheated, such as chairs, tables and trees. In a way physical objects have more insistent perceptive power than sense-objects. Attention to the fact of their occurrence in nature is the first condition for the survival of complex living or- ganisms. The result of this high perceptive power of physical objects is the scholastic philosophy of nature which looks on the sense-objects as mere attributes of the physical objects. This scholastic point of view is directly contradicted by the wealth of sense-objects which enter into our experience as situated in events without any connexion with physical objects. For example, stray smells, sounds, colours and more subtle nameless sense-objects. There is no perception of physical objects without perception of sense-objects. But the converse does not hold: namely, there is abundant perception of sense-objects unaccompanied by any perception of physical objects. This lack of reciprocity in the relations between sense-objects and physical objects is fatal to the scholastic natural philo- sophy.
Vii] Objects 157
There is a great difference in the rdles of the situa-
tions of sense-objects and physical objects. The situa-
tions of a physical object are conditioned by uniqueness
and continuity. The uniqueness is an ideal limit to
which we approximate as we proceed in thought along
an abstractive set of durations, considering smaller
and smaller durations in the approach to the ideal limit
of the moment of time. In other words, when the
duration is small enough, the situation of the physical
object within that duration is practically unique.
The identification of the same physical object as being situated in distinct events in distinct durations is effected by the condition of continuity. This condition of continuity is the condition that a continuity of passage of events, each event being a situation of the object in its corresponding duration, can be found from the earlier to the later of the two given events. So far as the two events are practically adjacent in one specious present, this continuity of passage may be directly perceived. Otherwise it is a matter of judgment and inference.
The situations of a sense-object are not conditioned
by any such conditions either of uniqueness or of con-
tinuity. In any durations however small a sense-object
may have any number of situations separated from each
other. Thus two situations of a sense-object, either in
the same duration or in different durations, are not
necessarily connected by any continuous passage of
events which are also situations of that sense-object.
The characters of the conditioning events involved in the ingression of a sense-object into nature can be largely expressed in terms of the physical objects which are situated in those events. In one respect this is also a tautology. For the physical object is nothing else than
158 THE CONCEPT OF NATURE [CH.
the habitual concurrence of a certain set of sense-objects in one situation. Accordingly when we know all about the physical object, we thereby know its component sense-objects. But a physical object is a condition for the occurrence of sense-objects other than those which are its components. For example, the atmosphere causes the events which are its situations to be active con- ditioning events in the transmission of sound. A mirror which is itself a physical object is an active condition for the situation of a patch of colour behind it, due to the reflection of light in it.
Thus the origin of scientific knowledge is the en- deavour to express in terms of physical objects the various rdles of events as active conditions in the in- gression of sense-objects into nature. It is in the progress of this investigation that scientific objects emerge. They embody those aspects of the character of the situations of the physical objects which are most permanent and are expressible without reference to a multiple relation including a percipient event. Their relations to each other are also characterised by a certain simplicity and uniformity. Finally the characters of the observed physical objects and sense-objects can be expressed in terms of these scientific objects. In fact the whole point of the search for scientific objects is the endeavour to obtain this simple expression of the characters of events. These scientific objects are not themselves merely formulae for calculation ; because formulae must refer to things in nature, and the scientific objects are the things in nature to which the formulae refer.
A scientific object such as a definite electron is a
systematic correlation of the characters of all events
throughout all nature. It is an aspect of the systematic
vn] OBJECTS 159
character of nature. The electron is not merely where
its charge is. The charge is the quantitative character
of certain events due to the ingression of the electron
into nature. The electron is its whole field of force.
Namely the electron is the systematic way in which all
events are modified as the expression of its ingression.
The situation of an electron in any small duration may
be defined as that event which has the quantitative
character which is the charge of the electron. We may
if we please term the mere charge the electron. But
then another name is required for the scientific object
which is the full entity which concerns science, and
which I have called the electron.
According to this conception of scientific objects, the rival theories of action at a distance and action by transmission through a medium are both incomplete expressions of the true process of nature. The stream of events which form the continuous series of situations of the electron is entirely self-determined, both as regards having the intrinsic character of being the series of situations of that electron and as regards the time- . systems with which its various members are cogredient, and the flux of their positions in their corresponding durations. This is the foundation of the denial of action at a distance ; namely the progress of the stream of the situations of a scientific object can be determined by an analysis of the stream itself.
On the other hand the ingression of every electron
into nature modifies to some extent the character of
every event. Thus the character of the stream of events
which we are considering bears marks of the existence
of every other electron throughout the universe. If we
like to think of the electrons as being merely what I call
i6o THE CONCEPT OF JN A iUKr, i^n.
their charges, then the charges act at a distance. But this action consists in the modification of the situation of the other electron under consideration. This con- ception of a charge acting at a distance is a wholly artificial one. The conception which most fully expresses the character of nature is that of each event as modified by the ingression of each electron into nature. The ether is the expression of this systematic modification of events throughout space and throughout time. The best expres- sion of the character of this modification is for physicists to find out. My theory has nothing to do with that and is ready to accept any outcome of physical research.
The connexion of objects with space requires eluci- dation. Objects are situated in events. The relation of situation is a different relation for each type of object, and in the case of sense-objects it cannot be expressed as a two-termed relation. It would perhaps be better to use a different word for these different types of the relation of situation. It has not however been necessary to do so for our purposes in these lectures. It must be understood however that, when situation is spoken of, some one definite type is under discussion, and it may happen that the argument may not apply to situation of another type. In all cases however I use situation to express a relation between objects and events and not between objects and abstractive elements. There is a derivative relation between objects and spatial elements which I call the relation of location; and when this relation holds, I say that the object is located in the abstractive element. In this sense, an object may be located in a moment of time, in a volume of space, an area, a line, or a point. There will be a peculiar type of location corresponding to each type of situation; and
VII] OBJECTS i6i
location is in each case derivative from the corresponding
relation of situation in a way which I will proceed to
explain.
Also location in the timeless space of some time-system is a relation derivative from location in instantaneous spaces of the same time-system. Accordingly location in an instantaneous space is the primary idea which we have to explain. Great confusion has been occasioned in natural philosophy by the neglect to distinguish be- tween the different types of objects, the different types of situation, the different types of location, and the difference between location and situation. It is im- possible to reason accurately in the vague concerning objects and their positions without keeping these dis- tinctions in view. An object is located in an abstractive element, when an abstractive set belonging to that ele- ment can be found such that each event belonging to that set is a situation of the object. It will be remem- bered that an abstractive element is a certain group of abstractive sets, and that each abstractive set is a set of events. This definition defines the location of an element in any type of abstractive element. In this sense we can talk of the existence of an object at an instant, meaning thereby its location in some definite moment. It may also be located in some spatial element of the instantaneous space of that moment.
A quantity can be said to be located in an abstractive
element when an abstractive set belonging to the element
can be found such that the quantitative expressions of
the corresponding characters of its events converge to
the measure of the given quantity as a limit when we
pass along the abstractive set towards its converging
end.
W.N. ^^
i62 THE CONCEPT OF NATURE [ch.
By these definitions location in elements of instanta- neous spaces is defined. These elements occupy corre- sponding elements of timeless spaces. An object located in an element of an instantaneous space will also be said to be located at that moment in the timeless element of the timeless space which is occupied by that instantaneous element.
It is not every object which can be located in a moment.
An object which can be located in every moment of some
duration will be called a 'uniform' object throughout
that duration. Ordinary physical objects appear to us
to be uniform objects, and we habitually assume that
scientific objects such as electrons are uniform. But
some sense-objects certainly are not uniform. A tune
is an example of a non-uniform object. We have per-
ceived it as a whole in a certain duration ; but the tune
as a tune is not at any moment of that duration though
one of the individual notes may be located there.
It is possible therefore that for the existence of
certain sorts of objects, e.g. electrons, minimum quanta
of time are requisite. Some such postulate is apparently
indicated by the modern quantum theory and it is per-
fectly consistent with the doctrine of objects maintained
in these lectures.
Also the instance of the distinction between the electron as the mere quantitative electric charge of its situation and the electron as standing for the ingression of an object throughout nature illustrates the indefinite number of types of objects which exist in nature. We can intellectually distinguish even subtler and subtler types of objects. Here I reckon subtlety as meaning seclusion from the immediate apprehension of sense- awareness. Evolution in the complexity of life means an
vii] OBJECTS 163