'MATTER SPACE TIME 229
to very primitive structural speculations on words, and to some un-sane ascribing of objectivity to words, can be abolished quite simply if we decide to investigate and re-educate our s.r.
What we know positively about 'space' is that it is not 'emptiness', but 'fulness', or a 'plenum'. Now 'fulness' or a 'plenum', first of all, is a term of entirely different non-el structure. When we have a plenum or fulness, it must be a plenum of 'something', 'somewhere', at 'some time', and so the term implies, at least, all three of our former elemen-talistic terms. Furthermore, fulness by some psycho-logical process does not require 'outside walls'. If we ask if such a universe of fulness is 'finite' or 'infinite', without any psycho-logical difficulties, we may reply that we do not know, but if we study enough of the materials of this universe we may know. A universe of fulness may be assumed to have boundaries, and then we may ask again the annoying question: What is beyond? With the proper use of language, this difficulty is again eliminated.
Without going into unnecessary details, we see that a boundary, or a limit, or a wall, is something by definition, beyond which we cannot go. If there is nothing to restrict our progress, there are no boundaries. Let us fancy some cosmic traveller with some extraordinary flying machine, and let us assume that he flies without stopping in a 'definite direction'. If he never encounters any boundary, he is surely entitled to say that his universe is unbounded. The question may arise: Is such an unbounded universe finite or infinite in size? Again let us apply correct language and a little analogy. A traveller on a sphere, like our own earth, could travel endlessly without ever coming to a boundary, and yet we know that the sphere, our earth, is of finite size. Mathematicians have worked out this point, and it is embodied in the Einstein theory. The universe is unbounded, an answer which satisfies our feelings ; yet it is finite in size, although very large, an answer which satisfies our rationality.* The visualization of such a universe is quite difficult. It should not be visualized as a sphere, but, at a later stage, we will see that it can be visualized satisfactorily. The condition for visualization is to eliminate identification, that semantic disturbance which is strictly connected with primitive ways of 'thinking'.
The problems of 'time' are similar, although they have a different neurological background. The rough materials we deal with mostly affect our sight, touch,. Invisible materials, like air., affect these 'senses'
*I do not introduce here the latest speculations in this field, because, from a non^aristotelian point of view, they appear meaningless.