es in the Phenomena of Light and
Heat," and of course he had never forgiven him. From that day forth a
relentless duel of wits between them had continued. Every essay,
monograph, or book that the one published, the other criticised with
cold but ruthless severity, to the great delectation of the scientific
world, if not to the clarification of its atmosphere.

Socially, they were cordial acquaintances, if not friends. What they
really thought of each other was known only to themselves and to their
immediate domestic circles.

Naturally Professor Marmion was well aware that his elevation to the
higher plane of N4 gave him an enormous advantage over his adversary,
for now he could, if he chose, smite him hip and thigh, in a strictly
scientific sense, and reduce him to utter confusion and public ridicule,
and the question which he had come to discuss with himself was: In how
far, if at all, was he justified in so using the extra-human powers with
which he had been endowed?

The moment that he began to do this he became conscious of another
curious complication of his recent development. On the higher plane he
had argued the matter out with no more emotion than a calculating
machine would have betrayed, and he had come to a conclusion that was
absolutely luminous and just: but now that he came to argue the same
question on the lower plane he found that he was doing it under human
limitations, and therefore with human feelings.

"No," he said in the peculiar low, musing tone which was habitual to him
during these monologues, "no; after all, I do not see that there would
be any harm in that. Wrong, nay, sinful it would undoubtedly be to prove
to demonstration that religious, social, and physical laws, may, under
certain changing circumstances, be both true and false at the same time.
I am, or was--or whatever it is--perfectly right in considering that to
deliberately produce such a chaos as that would do would be the most
colossal crime that a man could commit against humanity, as far as this
plane is concerned, but there can be no harm in making a few
mathematical experiments."

He took a few more turns up and down the room, pulling slowly at his
pipe, and with his mind not wholly unoccupied with speculations as to
what Professor Van Huysman's feelings might be if he were watching the
said experiments. Then he began again:

"At the worst I shall only be carrying certain investigations a few
steps farther, and developi