Buckmaster perceived that these men were catching glimpses of something which they called Will, Order, Thing, Absolute, and other names but which were all very probably the same thing—and also that which he sought. Eagerly he read on.
His next clue came from Bergson: Thought may begin with its object, and at last, in consistency, be driven, by the apparent necessities of logic, to conceive all things as forms and creatures of mind.
Quickly he passed on to Spinoza where he found a wealth of food for thought. Is the body merely an idea?
Is all the mentality that is scattered over space and time, a diffused consciousness that animates the world?
There is but one entity, seen now inwardly as mind, now outwardly as matter, but in reality an inextricable mixture and unity of both.
Eternal order ... that betokens the very structure of existence, underlying all events and things, and constituting the essence of the world.
Substance is insubstantial, that it is form and not matter, that it had nothing to do with that mongrel and neuter composite of matter.
Bruno said: All reality is one in substance, one in cause, one in origin; mind and matter are one.
Descartes' conception of a homogeneous "substance" underlying all forms of matter intrigued him for a time, and he wrestled mentally with the classic quotation, I think, therefore I am.
Berkeley wrote: A "thing" is merely a bundle of perceptions—i. e., classified and interpreted sensations.