It might be objected that space itself is a measure, and when we cannot measure it we cannot know it. No doubt if the terrestrial globe were 100 times smaller, 8 feet would barely be as long as one inch, and the man measuring “6 feet” from head to foot would really only be ¾ inch high. But nothing would appear smaller, because the metre would still be the ten-millionth part of the quarter circumference of the Earth, and everything would be reduced in the same proportion. As in the case of time, measurement is essentially relative and has nothing absolute about it. But this does not alter the fact that time only exists by the succession of events, whereas space exists absolutely. Empty space, which is nothing to our senses unless we measure it by some length, cannot be suppressed. Whether we measure it or not this is nothing to do with its existence by itself. These measures of space which we take have no common measure with infinity, nor with absolute space; yet they are taken in absolute space, and depend upon our means of observation. In the infinite void we can imagine several measures of space, all very different: for example, a fourth dimension which for us has no dimensions at all, and in which modes of investigation unknown to us can discover other dimensions which we cannot even guess at, since for us three dimensions exhaust all possible measurements of space. * * * * * The past which is no longer in existence, the future which is not yet, is contained as a germ in the present. To the universal eye, everything is in the present. In transporting ourselves, as we have done, into future times, we observe the events of those future times as if they were already present and already past. We are ephemeral atoms floating in the bosom of eternity, seen for an instant in a beam of light. We regard our epoch as a permanent reality--the illusion of a grain of dust which appears and disappears in the beam. He who contemplates nature must live in those ages as yet uncreated as well as in those which have passed away. And the future as well as the past are even more real than the present, which does not exist, since from one second to another time climbs up into the future only to fall Lack into the pit of the past. Shall we say that the “present” is the present hour? No, for an hour is long. The present minute? No, for the minute is long to the observing astronomer or physicist. The present second! No, for it is exceedingly long to electrify. Shall we reduce the “present” to the tenth of a second? Yes, if you like, but it is still relative to our sensations. Still, let us agree to that. Here, then, is the present--a tenth of a second! All the rest is past or future, and eternity is the only permanent reality. * * * * *