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.