To sum up: the termini for thought are entities,
I] Nature and Thought 13
primarily with bare individuality, secondarily with
properties and relations ascribed to them in the pro-
cedure of thought ; the termini for sense-awareness are
factors in the fact of nature, primarily relata and only
secondarily discriminated as distinct individualities.
No characteristic of nature which is immediately
posited for knowledge by sense-awareness can be
explained. It is impenetrable by thought, in the sense
that its peculiar essential character which enters into
experience by sense-awareness is for thought merely the
guardian of its individuality as a bare entity. Thus for
thought 'red' is merely a definite entity, though for
awareness * red ' has the content of its individuality. The
transition from the 'red' of awareness to the 'red' of
thought is accompanied by a definite loss of content,
namely by the transition from the factor 'red' to the
entity 'red.' This loss in the transition to thought is
compensated by the fact that thought is communicable
whereas sense-awareness is incommunicable.
Thus there are three components in our knowledge of nature, namely, fact, factors, and entities. Fact is the undiff"erentiated terminus of sense-awareness; factors are termini of sense-awareness, diff"erentiated as elements of fact ; entities are factors in their function as the ter- mini of thought. The entities thus spoken of are natural entities. Thought is wider than nature, so that there are entities for thought which are not natural entities.
When we speak of nature as a complex of related entities, the 'complex' is fact as an entity for thought, to whose bare individuality is ascribed the property of embracing in its complexity the natural entities. It is our business to analyse this conception and in the course of the analysis space and time should appear. Evidently
14 THE CONCEPT OF NATURE [CH.
Ithe relations holding between natural entities are
4hemselves natural entities, namely they are also factors
of fact, there for sense-awareness. Accordingly the
structure of the natural complex can never be com-
pleted in thought, just as the factors of fact can never
be exhausted in sense-awareness. Unexhaustiveness is
an essential character of our knowledge of nature. Also
nature does not exhaust the matter for thought, namely
there are thoughts which would not occur in any homo-
geneous thinking about nature.
The question as to whether sense-perception involves
thought is largely verbal. If sense-perception involves
a cognition of individuality abstracted from the actual
position of the entity as a factor in fact, then ii un-
doubtedly does involve thought. But if it is conceived
as sense-awareness of a factor in fact competent to
evoke emotion and purposeful action without further
cognition, then it does not involve thought. In such a
case the terminus of the sense-awareness is something
for mind, but nothing for thought. The sense-perception
of some lower forms of life may be conjectured to
approximate to this character habitually. Also occasion-
ally our own sense-perception in moments when thought-
activity has been lulled to quiescence is not far off the
attainment of this ideal limit.
The process of discrimination in sense-awareness has
two distinct sides. There is the discrimination of fact
into parts, and the discrimination of any part of fact as
exhibiting relations to entities which are not parts of
fact though they are ingredients in it. Namely the^
immediate fact for awareness is the whole occurrence
Df nature. It is nature as an event present for sense- ,
iwareness, and essentially passing. There is no holding
I] Nature and Thought 15
nature still and looking at it. We cannot redouble our
eiforts to improve our knowledge of the terminus of our
present sense-awareness; it is our subsequent oppor-
tunity in subsequent sense-awareness which gains the
benefit of our good resolution. Thus the ultimate fact
for sense-awareness is an event. This whole event is
discriminated by us into partial events. We are aware
of an event which is our bodily life, of an event which is
the course of nature jwithin thisraom^ and of a vaguely
perceived aggregate of other partial events. This is the
discrimination in sense-awareness of fact into parts.
I shall use the term 'part' in the arbitrarily limited
sense of an event which is part of the whole fact dis-
closed in awareness.
Sense-awareness also yields to us other factors in nature which are not events. For example, sky-blue is seen as situated in a certain event. This relation of situation requires further discussion which is postponed to a later lecture. My present point is that sky-blue is found in nature with a definite implication in events, but is not an event itself. Accordingly in addition to events, there are other factors in nature directly dis-^ closed to us in sense-awareness. The conception in thought of all the factors in nature as distinct entities with definite natural relations is what I have in another place^ called the 'diversification of nature.'
There is one general conclusion to be drawn from the foregoing discussion. It is that the first task of a philo- sophy of science should be some general classification of the entities disclosed to us in sense-perception.
Among the examples of entities in addition to ' events ' which we have used for the purpose of illustration are
1 Cf. Enquiry.
i6 THE CONCEPT OF NATURE [ch.
the buildings of Bedford College, Homer, and sky-blue. Evidently these are very different sorts of things ; and it is likely that statements which are made about one kmd of entity will not be true about other kinds. If human thought proceeded with the orderly method which abstract logic would suggest to it, we might go further and say that a classification of natural entities should be the first step in science itself. Perhaps you will be inclined to reply that this classification has already been effected, and that science is concerned with the ad- ventures of material entities in space and time.
The history of the doctrine of matter has yet to be written. It is the history of the influence of Greek philosophy on science. That influence has issued in one long misconception of the metaphysical status of natural entities. The entity has been separated from the factor which is the terminus of sense-awareness. It has become the substratum for that factor, and the factor has been degraded into an attribute of the entity. In this way a distinction has been imported into nature which is in truth no distinction at all. A natural entity is merely a factor of fact, considered in itself. Its dis- connexion from the complex of fact is a mere abstraction. It is not the substratum of the factor, but the very factor itself as bared in thought. Thus what is a mere procedure of mind in the translation of sense-awareness into discursive knowledge has been transmuted into a fundamental character of nature. In this way matter has emerged as being the metaphysical substratum of its properties, and the course of nature is interpreted as the history of matter.
Plato and Aristotle found Greek thought preoccupied with the quest for the simple substances in terms of
Nature and Thought 17
hich the course of events could be expressed. We ay formulate this state of mind in the question, What
nature made of? The answers which their genius
ive to this question, and more particularly the con-
;pts which underlay the terms in which they framed
leir answers, have determined the unquestioned pre-
ippositions as to time, space and matter which have
;igned in science.
In Plato the forms of thought are more fluid than in
ristotle, and therefore, as I venture to think, the more
iluable. Their importance consists in the evidence
ley yield of cultivated thought about nature before it
ad been forced into a uniform mould by the long
adition of scientific philosophy. For example in the
imaeus there is a presupposition, somewhat vaguely
^pressed, of a distinction between the general becoming
F nature and the measurable time of nature. In a later
:cture I have to distinguish between what I call the
assage of nature and particular time-systems which
sihibit certain characteristics of that passage. I will not
so far as to claim Plato in direct support of this
octrine, but I do think that the sections of the Timaeus
'hich deal with time become clearer if my distinction
i admitted.
This is however a digression. I am now concerned
ith the origin of the scientific doctrine of matter in
Jreek thought. In the Timaeus Plato asserts that nature
1 made of fire and earth with air and water as inter- lediate between them, so that ' as fire is to air so is air ) water, and as air is to water so is water to earth.' He [so suggests a molecular hypothesis for these four iements. In this hypothesis everything depends on the bape of the atoms ; for earth it is cubical and for fire
W. N, 2
i8 THE CONCEPT OF NATURE [ch.
it is pyramidal. To-day physicists are again discussing the structure of the atom, and its shape is no sHght factor in that structure. Plato's guesses read much more fantastically than does Aristotle's systematic analysis; but in some ways they are more valuable. The main outline of his ideas is comparable with that of modern science. It embodies concepts which any theory of natural philosophy must retain and in some sense must explain. Aristotle asked the fundamental question, What do we mean by ' substance ' ? Here the reaction between his philosophy and his logic worked very unfortunately. In his logic, the fundamental type of affirmative proposition is the attribution of a predicate to a subject. Accordingly, amid the many current uses of the term ' substance ' which he analyses, he emphasises its meaning as 'the ultimate substratum which is no longer predicated of anything else.'
The unquestioned acceptance of the Aristotelian logic
has led to an ingrained tendency to postulate a sub-
stratum for whatever is disclosed in sense-awareness,
namely, to look below what we are aware of for the
substance in the sense of the 'concrete thing.' This
is the origin of the modern scientific concept of matter
and of ether, namely they are the outcome of this
insistent habit of postulation.
Accordingly ether has been invented by modern science as the substratum of the events which are spread through space and time beyond the reach of ordinary ponderable matter. Personally, I think that predication is a muddled notion confusing many different relations under a convenient common form of speech. For example, I hold that the relation of green to a blade of grass is entirely different from the relation of green
1] Nature and Thought 19
to the event which is the Hfe history of that blade for
some short period, and is different from the relation
of the blade to that event. In a sense I call the
event the situation of the green, and in another sense
it is the situation of the blade. Thus in one sense the
blade is a character or property which can be predi-
cated of the situation, and in another sense the green
is a character or property of the same event which
is also its situation. In this way the predication of
properties veils radically different relations between
entities.
Accordingly ' substance,' which is a correlative term
to * predication,' shares in the ambiguity. If we are to
look for substance anywhere, I should find it in events
which are in some sense the ultimate substance of
nature.
Matter, in its modern scientific sense, is a return to
the Ionian effort to find in space and time some stuff
which composes nature. It has a more refined signi-
fication than the early guesses at earth and water by
reason of a certain vague association with the Aristotelian
idea of substance.
Earth, water, air, fire, and matter, and finally ether are related in direct succession so far as concerns their postulated characters of ultimate substrata of nature. They bear witness to the undying vitality of Greek philosophy in its search for the ultimate entities which are the factors of the fact disclosed in sense-awareness / This search is the origin of science.
The succession of ideas starting from the crude
guesses of the early Ionian thinkers and ending in the
nineteenth century ether reminds us that the scientific
doctrine of matter is really a hybrid through which
20 THE CONCEPT OF NATURE [CH.