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 to
the event which is the life 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 predicated 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 signification 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
philosophy passed on its way to the refined Aristotelian concept of
substance and to which science returned as it reacted against
philosophic abstractions. Earth, fire, and water in the Ionic philosophy
and the shaped elements in the _Timaeus_ are comparable to the matter
and ether of modern scientific doctrine. But substance represents the
final philosophic concept of the substratum which underlies any
attribute. Matter (in the scientific sense) is already in space