However, for reasons discussed earlier, Einstein was forced to conceive
all events in the universe after the model of gravity as observable on
the earth. In this way he arrived at a space-structure which possesses
neither the three-dimensionality nor the rectilinear character of
so-called Euclidean space - a space-picture which, though
mathematically consistent, is incomprehensible by the human mind. For
nothing exists in our mind that could enable us to experience as a
reality a space-time continuum of three dimensions which is curved
within a further dimension.

This outcome of Einstein's endeavours results from the fact that he
tried by means of gravity-bound thought to comprehend universal
happenings of which the true causes are non-gravitational. A thinking
that has learnt to acknowledge the existence of levity must indeed
pursue precisely the opposite direction. Instead of freezing time down
into spatial dimension, in order to make it fit into a world ruled by
nothing but gravity, we must develop a conception of space sufficiently
fluid to let true time have its place therein. We shall see how such a
procedure will lead us to a space-concept thoroughly conceivable by
human common sense, provided we are prepared to overcome the
onlooker-standpoint in mathematics also.

Einstein owed the possibility of establishing his space-picture to a
certain achievement of mathematical thinking in modern times. As we
have seen, one of the peculiarities of the onlooker-consciousness
consists in its being devoid of all connexion with reality. The process
of thinking thereby gained a degree of freedom which did not exist in
former ages. In consequence, mathematicians were enabled in the course
of the nineteenth century to conceive the most varied space-systems